Document:

EX-10.1

 Exhibit 10.1 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

1.    Purposes of the Plan. The purposes of this Twist Bioscience Corporation 2013 Stock Plan are to
attract and retain the best available personnel for positions of substantial responsibility, to provide additional incentive to Employees and Consultants, and to promote the success of the Company’s business. Options granted under the Plan may
be Incentive Stock Options or Nonstatutory Stock Options, as determined by the Administrator at the time of grant of an Option and subject to the applicable provisions of Section 422 of the Code and the regulations promulgated thereunder.
Restricted Stock may also be granted under the Plan. 
 2.    Definitions. As used herein, the
following definitions shall apply: 
 (a)    “Administrator” means the Board or a
Committee. 
 (b)    “Affiliate” means (i) an entity other than a Subsidiary
which, together with the Company, is under common control of a third person or entity and (ii) an entity other than a Subsidiary in which the Company and /or one or more Subsidiaries own a controlling interest. 

(c)    “Applicable Laws” means all applicable laws, rules, regulations and
requirements, including, but not limited to, all applicable U.S. federal or state laws, any Stock Exchange rules or regulations, and the applicable laws, rules or regulations of any other country or jurisdiction where Options or Restricted Stock are
granted under the Plan or Participants reside or provide services, as such laws, rules, and regulations shall be in effect from time to time. 

(d)    “Award” means any award of an Option or Restricted Stock under the Plan. 

(e)    “Award Agreement” means a written document (e.g., an Option Agreement, Restricted Stock
Award Agreement or Restricted Stock Purchase Agreement), the form(s) of which shall be approved from time to time by the Administrator, reflecting the terms of an Award granted under the Plan and includes any documents attached to or incorporated
into such Award. 
 (f)     “Board” means the Board of Directors of the Company.

 (g)    “California Participant” means a Participant whose Award is issued in
reliance on Section 25102(o) of the California Corporations Code. 
 (h)    “Cashless
Exercise” means a program approved by the Administrator in which payment of the exercise price and/or tax withholding obligations or other required deductions may be satisfied, in whole or in part, with Shares subject to the
Award, including by delivery of an irrevocable direction to a securities broker (on a form prescribed by the Company) to sell Shares and to deliver all or part of the sale proceeds to the Company in payment of such amount. 

 (i)    “Cause” means, with respect to
the termination of a Participant’s Continuous Service Status, except as otherwise defined in an Award Agreement, (i) in the case where there is no employment agreement, consulting agreement, change in control agreement or similar agreement
in effect between the Company or an Affiliate of the Company and the Participant at the time of the grant of the Award (or where there is such an agreement but it does not define “cause” (or words of like import) or where it only applies
upon the occurrence of a change in control and one has not yet taken place): (A) any material breach by Participant of any material written agreement between Participant and the Company; (B) any failure by Participant to comply with the
Company’s material written policies or rules as they may be in effect from time to time; (C) neglect or persistent unsatisfactory performance of Participant’s duties; (D) Participant’s repeated failure to follow reasonable
and lawful instructions from the Board or Chief Executive Officer; (E) Participant’s indictment for, conviction of, or plea of guilty or nolo contendre to, any felony or crime that results in, or is reasonably expected to result in, a
material adverse effect on the business or reputation of the Company; (F) Participant’s commission of or participation in an act of fraud against the Company; (G) Participant’s intentional material damage to the Company’s
business, property or reputation; or (H) Participant’s unauthorized use or disclosure of any proprietary information or trade secrets of the Company or any other party to whom the Participant owes an obligation of nondisclosure as a result
of his or her relationship with the Company; or (ii) in the case where there is an employment agreement, consulting agreement, change in control agreement or similar agreement in effect between the Company or an Affiliate and the Participant at
the time of the grant of the Award that defines “cause” (or words of like import), “cause” as defined under such agreement; provided, however, that with regard to any agreement under which the definition of “cause” only
applies on occurrence of a change in control, such definition of “cause” shall not apply until a change in control actually takes place and then only with regard to a termination thereafter. For purposes of clarity, a termination without
“Cause” does not include any termination that occurs solely as a result of Participant’s death or Disability. The determination as to whether a Participant’s Continuous Service Status has been terminated for Cause shall be made
in good faith by the Company and shall be final and binding on the Participant. The foregoing definition does not in any way limit the Company’s ability to terminate a Participant’s employment or consulting relationship at any time, and
the term “Company” will be interpreted to include any Subsidiary, Parent, Affiliate, or any successor thereto, if appropriate. 

(j)     “Code” means the Internal Revenue Code of 1986, as amended, and any
successor thereto. Reference in the Plan to any section of the Code shall be deemed to include any regulations or other interpretative guidance under such section, and any amendments or successor provisions to such section, regulations or guidance.

 (k)    “Committee” means one or more committees or subcommittees of the Board
consisting of two (2) or more Directors (or such lesser or greater number of Directors as shall constitute the minimum number permitted by Applicable Laws to establish a committee or sub-committee of the
Board) appointed by the Board to administer the Plan in accordance with Section 4 below. 

(l)    “Common Stock” means the Company’s common stock, par value $0.00001 per
share, as adjusted pursuant to Section 10 below. 
 (m)    “Company” means
Twist Bioscience Corporation, a Delaware corporation. 

  
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 (n)    “Consultant” means any person or
entity, including an advisor but not an Employee, that renders, or has rendered, services to the Company, or any Parent, Subsidiary or Affiliate and is compensated for such services, and any non-Employee
Director whether compensated for such services or not. 
 (o)    “Continuous Service
Status” means the absence of any interruption or termination of service as an Employee or Consultant. Continuous Service Status as an Employee or Consultant shall not be considered interrupted or terminated in the case of:
(i) Company approved sick leave; (ii) military leave; (iii) any other bona fide leave of absence approved by the Company, provided that, if an Employee is holding an Incentive Stock Option and such leave exceeds 3 months, such
Employee’s service as an Employee shall be deemed terminated on the 1st day following such 3-month period and the Incentive Stock Option shall thereafter automatically become a Nonstatutory Stock Option
in accordance with Applicable Laws, unless reemployment upon the expiration of such leave is guaranteed by contract or statute, or unless provided otherwise pursuant to a written Company policy. Also, Continuous Service Status as an Employee or
Consultant shall not be considered interrupted or terminated in the case of a transfer between locations of the Company or between the Company, its Parents, Subsidiaries or Affiliates, or their respective successors, or a change in status from an
Employee to a Consultant or from a Consultant to an Employee. 
 (p)    “Director”
means a member of the Board. 
 (q)    “Disability” means
“disability” within the meaning of Section 22(e)(3) of the Code. 

(r)    “Employee” means any person employed by the Company, or any Parent,
Subsidiary or Affiliate, with the status of employment determined pursuant to such factors as are deemed appropriate by the Company in its sole discretion, subject to any requirements of Applicable Laws, including the Code. The payment by the
Company of a director’s fee shall not be sufficient to constitute “employment” of such director by the Company or any Parent, Subsidiary or Affiliate. 

(s)    “Exchange Act” means the Securities Exchange Act of 1934, as amended. 

(t)    “Fair Market Value” means, unless otherwise required by any applicable
provision of the Code, with respect to a share of Common Stock or other security, as of any date, the closing price reported for the Common Stock on the applicable date: (a) as reported on the principal national securities exchange in the
United States on which it is then traded; or (b) if not traded on any such national securities exchange, as quoted on an automated quotation system sponsored by the Financial Industry Regulatory Authority, or if the Common Stock shall not have
been reported or quoted on such date, on the first day prior thereto on which the Common Stock was reported or quoted. If the Common Stock is not traded, listed or otherwise reported or quoted, then Fair Market Value means the fair market value of a
share of Common Stock as determined by the Board or Committee in good faith on such basis as it deems appropriate and applied consistently with respect to Participants, taking into account the requirements of Section 422 of the Code or
Section 409A of the Code, as applicable. 

  
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 (u)    “Family Members” means any
child, stepchild, grandchild, parent, stepparent, grandparent, spouse, former spouse, sibling, niece, nephew, mother-in-law, father-in-law, son-in-law, daughter-in-law, brother-in-law, or sister-in-law (including adoptive relationships) of the Participant, any
person sharing the Participant’s household (other than a tenant or employee), a trust in which these persons (or the Participant) have more than 50% of the beneficial interest, a foundation in which these persons (or the Participant) control
the management of assets, and any other entity in which these persons (or the Participant) own more than 50% of the voting interests. 

(v)    “Incentive Stock Option” means an Option intended to, and which does, in
fact, qualify as an incentive stock option within the meaning of Section 422 of the Code. 

(w)    “Involuntary Termination” means (unless another definition is provided in the
applicable Award Agreement, employment agreement or other applicable written agreement) the termination of a Participant’s Continuous Service Status other than for (i) death, (ii) Disability or (iii) for Cause by the Company or a
Parent, Subsidiary, Affiliate or successor thereto, as appropriate. 
 (x)    “Listed
Security” means any security of the Company that is listed or approved for listing on a national securities exchange or designated or approved for designation as a national market system security on an interdealer
quotation system by the Financial Industry Regulatory Authority (or any successor thereto). 

(y)    “Nonstatutory Stock Option” means an Option that is not intended to, or does
not, in fact, qualify as an Incentive Stock Option. 
 (z)    “Option” means a
stock option granted pursuant to the Plan. 
 (aa)    “Option Agreement” means a
written document, the form(s) of which shall be approved from time to time by the Administrator, reflecting the terms of an Option granted under the Plan and includes any documents attached to or incorporated into such Option Agreement, including,
but not limited to, a notice of stock option grant and a form of exercise notice. 
 (bb)    “Optioned
Stock” means Shares that are subject to an Option or that were issued pursuant to the exercise of an Option. 

(cc)    “Optionee” means an Employee or Consultant who receives an Option. 

(dd)    “Parent” means any corporation (other than the Company) in an unbroken chain
of corporations ending with the Company if, at the time of grant of the Award, each of the corporations other than the Company owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other
corporations in such chain. A corporation that attains the status of a Parent on a date after the adoption of the Plan shall be considered a Parent commencing as of such date. 

(ee)    “Participant” means any holder of one or more Awards or Shares issued
pursuant to an Award. 

  
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 (ff)    “Plan” means this Twist
Bioscience Corporation 2013 Stock Plan. 
 (gg)    “Registration Rights Agreement”
means the Company’s Registration Rights Agreement, dated as of July 1, 2013, 2013, by and among the Company and the other stockholders party thereto, as the same may thereafter be amended from time to time in accordance with its terms.

 (hh)     “Restricted Stock” means Shares acquired pursuant to a right to
purchase or receive Common Stock granted pursuant to Section 8 below. 
 (ii)    “Rule 16b-3” means Rule 16b-3 promulgated under the Exchange Act, as amended from time to time, or any successor provision. 

(jj)    “Share” means a share of Common Stock, as adjusted in accordance with
Section 10 below. 
 (kk)    “Stock Exchange” means any stock exchange or
consolidated stock price reporting system on which prices for the Common Stock are quoted at any given time. 

(ll)    “Stockholders Agreement” shall mean the Stockholders Agreement, dated as of July 1,
2013 by and among the Company and the other stockholders party thereto, as the same may thereafter be amended from time to time in accordance with its terms. 

(mm)    “Subsidiary” means any corporation (other than the Company) in an unbroken
chain of corporations beginning with the Company if, at the time of grant of the Award, each of the corporations other than the last corporation in the unbroken chain owns stock possessing 50% or more of the total combined voting power of all
classes of stock in one of the other corporations in such chain. A corporation that attains the status of a Subsidiary on a date after the adoption of the Plan shall be considered a Subsidiary commencing as of such date. 

(nn)    “Ten Percent Holder” means a person who owns stock representing more than
10% of the voting power of all classes of stock of the Company or any Parent or Subsidiary measured as of an Award’s date of grant. 

3.    Stock Subject to the Plan. Subject to the provisions of Section 10 below, the maximum
aggregate number of Shares that may be issued under the Plan is 34,306,102 Shares, all of which Shares may be issued under the Plan pursuant to Incentive Stock Options. The Shares issued under the Plan may be authorized, but unissued, or reacquired
Shares. If any Option Award granted under the Plan expires, terminates or is canceled for any reason without having been exercised in full, then such expired, terminated or cancelled Shares that were subject thereto shall become available for future
grant under the Plan. In addition, any Shares subject to a Restricted Stock Award issued under the Plan and later forfeited to the Company due to the failure to vest, and any Shares issued pursuant to a Restricted Stock Award that are repurchased by
the Company at the original purchase price paid to the Company for the Shares (including, without limitation, upon forfeiture to or repurchase by the Company in connection with the termination of a Participant’s Continuous Service Status, but
excluding, for the avoidance of doubt, any Shares repurchased at a price in excess of the original purchase price paid to the Company for the Shares), shall again be available for future grant under the Plan. The number of Shares of Common Stock

  
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available for the purpose of Awards under the Plan shall be reduced by (i) the total number of Options that have been exercised, regardless of whether any of the shares of Common Stock
underlying such Awards are not actually issued to the Participant as the result of a net settlement, and (ii) any shares of Common Stock used to pay any exercise price or tax withholding obligation with respect to any Award. Notwithstanding the
foregoing, subject to the provisions of Section 10 below, in no event shall the maximum aggregate number of Shares that may be issued under the Plan pursuant to Incentive Stock Options exceed the number set forth in the first sentence of this
Section 3 plus, to the extent allowable under Section 422 of the Code, any Shares that again become available for issuance pursuant to the remaining provisions of this Section 3. 

4.    Administration of the Plan. 

(a)    General. The Plan shall be administered by the Board, a Committee appointed by the Board, or
any combination thereof, as determined by the Board. The Plan may be administered by different administrative bodies with respect to different classes of Participants and, if permitted by Applicable Laws, the Board may authorize one or more officers
of the Company to make Awards under the Plan to Employees and Consultants (who are not subject to Section 16 of the Exchange Act) within parameters specified by the Board. 

(b)    Committee Composition. If a Committee has been appointed pursuant to this Section 4, such
Committee shall continue to serve in its designated capacity until otherwise directed by the Board. 

(c)    Powers of the Administrator. Subject to the provisions of the Plan and, in the case of a
Committee, the specific duties delegated by the Board to such Committee, the Administrator shall have the authority, in its sole discretion: 

(i)    to determine the Fair Market Value in accordance with Section 2(t) above, provided that such determination
shall be applied consistently with respect to Participants under the Plan; 
 (ii)    to select the Employees and
Consultants to whom Awards may from time to time be granted; 
 (iii)    to determine the number of Shares to be
covered by each Award; 
 (iv)    to approve the form(s) of agreement(s) and other related documents used under the
Plan; 
 (v)    to determine the terms and conditions, not inconsistent with the terms of the Plan, of any Award
granted hereunder, which terms and conditions include but are not limited to the exercise or purchase price, the time or times when Awards may vest and/or be exercised (which may be based on performance criteria), the circumstances (if any) when
vesting will be accelerated or forfeiture restrictions will be waived, and any restriction or limitation regarding any Award, Optioned Stock, or Restricted Stock; 

(vi)    to amend any outstanding Award or agreement related to any Optioned Stock or Restricted Stock, including any
amendment adjusting vesting (e.g., in 

  
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connection with a change in the terms or conditions under which such person is providing services to the Company), provided that no amendment shall be made that would materially and adversely
affect the rights of any Participant without his or her consent; 
 (vii)    to determine whether and under what
circumstances an Option may be settled in cash under Section 7(c)(iii) below instead of Common Stock; 

(viii)    to approve addenda pursuant to Section 18 below or to grant Awards to, or to modify the terms of, any
outstanding Award Agreement or any agreement related to any Optioned Stock or Restricted Stock held by Participants who are foreign nationals or employed outside of the United States with such terms and conditions as the Administrator deems
necessary or appropriate to accommodate differences in local law, tax policy or custom which deviate from the terms and conditions set forth in this Plan to the extent necessary or appropriate to accommodate such differences; and 

(ix)    to construe and interpret the terms of the Plan, any Award Agreement, and any agreement related to any Optioned
Stock or Restricted Stock, which constructions, interpretations and decisions shall be final and binding on all Participants. 

(d)    Indemnification. To the maximum extent permitted by Applicable Laws, each member of the
Committee (including officers of the Company, if applicable), or of the Board, as applicable, shall be indemnified and held harmless by the Company against and from (i) any loss, cost, liability, or expense that may be imposed upon or
reasonably incurred by him or her in connection with or resulting from any claim, action, suit, or proceeding to which he or she may be a party or in which he or she may be involved by reason of any action taken or failure to act under the Plan or
pursuant to the terms and conditions of any Award except for actions taken in bad faith or failures to act in bad faith, and (ii) any and all amounts paid by him or her in settlement thereof, with the Company’s approval, or paid by him or
her in satisfaction of any judgment in any such claim, action, suit, or proceeding against him or her, provided that such member shall give the Company an opportunity, at its own expense, to handle and defend any such claim, action, suit or
proceeding before he or she undertakes to handle and defend it on his or her own behalf. The foregoing right of indemnification shall not be exclusive of any other rights of indemnification to which such persons may be entitled under the
Company’s Certificate of Incorporation, Bylaws, the Stockholders Agreement, the Registration Rights Agreement, by contract, as a matter of law, or otherwise, or under any other power that the Company may have to indemnify or hold harmless each
such person. 
 5.    Eligibility. 

(a)    Recipients of Grants. Nonstatutory Stock Options and Restricted Stock may be granted to
Employees and Consultants. Incentive Stock Options may be granted only to Employees, provided that Employees of Affiliates shall not be eligible to receive Incentive Stock Options. 

(b)    No Employment Rights. Neither the Plan nor any Award shall confer upon any Employee or
Consultant any right with respect to continuation of an employment or consulting relationship with the Company (any Parent, Subsidiary or Affiliate), nor shall it interfere in any 

  
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way with such Employee’s or Consultant’s right or the Company’s (Parent’s, Subsidiary’s or Affiliate’s) right to terminate his or her employment or consulting
relationship at any time, with or without cause. 
 6.    Term of Plan. The Plan shall become
effective upon its adoption by the Board and shall continue in effect for a term of 10 years unless sooner terminated under Section 13 below. 

7.    Options. 

(a)    Term of Option. The term of each Option shall be the term stated in the Option Agreement;
provided that the term shall be no more than 10 years from the date of grant thereof or such shorter term as may be provided in the Option Agreement and provided further that, in the case of an Incentive Stock Option granted to a person who at the
time of such grant is a Ten Percent Holder, the term of the Option shall be 5 years from the date of grant thereof or such shorter term as may be provided in the Option Agreement. 

(b)    Type of Option. Each Option shall be designated in the Option Agreement as either an Incentive
Stock Option or a Nonstatutory Stock Option. 
 (c)    ISO $100,000 Limitation. Notwithstanding any
designation under Section 5(a) above, to the extent that the aggregate Fair Market Value of Shares with respect to which options designated as incentive stock options are exercisable for the first time by any Optionee during any calendar year
(under all plans of the Company or any Parent or Subsidiary) exceeds $100,000, such excess options shall be treated as nonstatutory stock options. For purposes of this Section 5(c), incentive stock options shall be taken into account in the
order in which they were granted, and the Fair Market Value of the Shares subject to an incentive stock option shall be determined as of the date of the grant of such option. 

(d)    Option Exercise Price and Consideration. 

(i)    Exercise Price. The per Share exercise price for the Shares to be issued pursuant to the
exercise of an Option shall be such price as is determined by the Administrator and set forth in the Option Agreement, but shall be subject to the following: 

(1)    In the case of an Incentive Stock Option 

a.    granted to an Employee who at the time of grant is a Ten Percent Holder, the per Share exercise price shall be no
less than 110% of the Fair Market Value per Share on the date of grant; 
 b.    granted to any other Employee, the per
Share exercise price shall be no less than 100% of the Fair Market Value per Share on the date of grant; 
 (2)    In
the case of a Nonstatutory Stock Option the per Share exercise price shall be no less than 100% of the Fair Market Value per Share on the date of grant. 

(ii)    Permissible Consideration. The consideration to be paid for the Shares to be issued upon
exercise of an Option, including the method of payment, shall be 

  
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determined by the Administrator (and, in the case of an Incentive Stock Option and to the extent required by Applicable Laws, shall be determined at the time of grant) and may consist entirely of
(1) cash; (2) check; (3) to the extent permitted under, and in accordance with, Applicable Laws and approved by the Committee, delivery of a promissory note with such recourse, interest, security and redemption provisions as the
Administrator determines to be appropriate (subject to the provisions of Section 152 of the General Corporation Law); (4) cancellation of indebtedness of the Company to the Participant; (5) other previously owned Shares (for which the
Participant has good title free and clear of any liens and encumbrances) that have a Fair Market Value on the date of surrender equal to the aggregate exercise price of the Shares as to which the Option is exercised; (6) a Cashless Exercise;
(7) such other consideration and method of payment permitted under Applicable Laws; or (8) any combination of the foregoing methods of payment. In making its determination as to the type of consideration to accept, the Administrator may,
in its sole discretion, refuse to accept a particular form of consideration at the time of any Option exercise. No Shares shall be issued until payment therefor, as provided herein, has been made or provided for. 

(e)    Exercise of Option. 

(i)    General. 

(1)    Exercisability. Any Option granted hereunder shall be exercisable at such times and under such
conditions as determined by the Administrator, consistent with the terms of the Plan and reflected in the Option Agreement, including vesting requirements and/or performance criteria with respect to the Company, and Parent, Subsidiary or Affiliate,
and/or the Optionee. 
 (2)    Leave of Absence. The Administrator shall have the discretion to
determine whether and to what extent the vesting of Options shall be tolled during any leave of absence; provided, however, that in the absence of such determination, vesting of Options shall be tolled during any leave (unless otherwise required by
Applicable Laws). Notwithstanding the foregoing, in the event of military leave, vesting shall toll during any unpaid portion of such leave, provided that, upon an Optionee’s returning from military leave (under conditions that would entitle
him or her to protection upon such return under the Uniform Services Employment and Reemployment Rights Act), he or she shall be given vesting credit with respect to Options to the same extent as would have applied had the Optionee continued to
provide services to the Company (or any Parent, Subsidiary or Affiliate, if applicable) throughout the leave on the same terms as he or she was providing services immediately prior to such leave. 

(3)    Minimum Exercise Requirements. An Option may not be exercised for a fraction of a Share. The
Administrator may require that an Option be exercised as to a minimum number of Shares, provided that such requirement shall not prevent an Optionee from exercising the full number of Shares as to which the Option is then exercisable. 

(4)    Procedures for and Results of Exercise. An Option shall be deemed exercised when written
notice of such exercise has been received by the Company in accordance with the terms of the Option Agreement by the person entitled to exercise the Option and the Company has received full payment for the Shares with respect to which the Option is

  
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exercised and has paid, or made arrangements to satisfy, any applicable taxes, withholding, required deductions or other required payments in accordance with Section 9 below. The exercise of
an Option shall result in a decrease in the number of Shares that thereafter may be available, both for purposes of the Plan and for sale under the Option, by the number of Shares as to which the Option is exercised. 

(5)    Rights as Holder of Capital Stock. Until the issuance of the Shares (as evidenced by the
appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a holder of capital stock shall exist with respect to the Optioned Stock,
notwithstanding the exercise of the Option. No adjustment will be made for a dividend or other right for which the record date is prior to the date the stock certificate is issued, except as provided in Section 10 below. 

(ii)    Termination of Continuous Service Status. The Administrator shall establish and set forth in
the applicable Option Agreement the terms and conditions upon which an Option shall remain exercisable, if at all, following termination of an Optionee’s Continuous Service Status, which provisions may be waived or modified by the Administrator
at any time. To the extent that an Option Agreement does not specify the terms and conditions upon which an Option shall terminate upon termination of an Optionee’s Continuous Service Status, the following provisions shall apply: 

(1)    General Provisions. If the Optionee (or other person entitled to exercise the Option) does
not exercise the Option to the extent so entitled within the time specified below, the Option shall terminate and the Optioned Stock underlying the unexercised portion of the Option shall revert to the Plan. In no event may any Option be exercised
after the expiration of the Option term as set forth in the Option Agreement (and subject to this Section 7). 

(2)    Termination other than Upon Disability or Death or for Cause. In the event of termination of
an Optionee’s Continuous Service Status other than under the circumstances set forth in the subsections (3) through (5) below, subject to Section 7(a) above, such Optionee may exercise any outstanding Option at any time within 3
month(s) following such termination to the extent the Optionee is vested in the Optioned Stock. 

(3)    Disability of Optionee. In the event of termination of an Optionee’s Continuous Service
Status as a result of his or her Disability, subject to Section 7(a) above, such Optionee may exercise any outstanding Option at any time within 12 month(s) following such termination to the extent the Optionee is vested in the Optioned Stock.

 (4)    Death of Optionee. In the event of the death of an Optionee during the period of
Continuous Service Status since the date of grant of any outstanding Option, or within 3 month(s) following termination of the Optionee’s Continuous Service Status, subject to Section 7(a) above, the Option may be exercised by any
beneficiaries designated in accordance with Section 16 below, or if there are no such beneficiaries, by the Optionee’s estate, or by a person who acquired the right to exercise the Option by bequest or inheritance, at any time within 12
month(s) following the date the Optionee’s Continuous Service Status terminated, but only to the extent the Optionee is vested in the Optioned Stock. 

  
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 (5)    Termination for Cause. In the event of
termination of an Optionee’s Continuous Service Status for Cause, any outstanding Option (including any vested portion thereof) held by such Optionee shall immediately terminate in its entirety upon first notification to the Optionee of
termination of the Optionee’s Continuous Service Status for Cause. If an Optionee’s Continuous Service Status is suspended pending an investigation of whether the Optionee’s Continuous Service Status will be terminated for Cause, all
the Optionee’s rights under any Option, including the right to exercise the Option, shall be suspended during the investigation period. Nothing in this Section 7(c)(ii)(5) shall in any way limit the Company’s right to purchase
unvested Shares issued upon exercise of an Option as set forth in the applicable Option Agreement. 

(iii)    Buyout Provisions. The Administrator may at any time offer to buy out for a payment in cash
or Shares an Option previously granted under the Plan based on such terms and conditions as the Administrator shall establish and communicate to the Optionee at the time that such offer is made, subject to Applicable Laws. 

8.    Restricted Stock. 

(a)    Rights to Purchase. When a right to purchase or receive Restricted Stock is granted under the
Plan, the Company shall advise the recipient in writing of the terms, conditions and restrictions related to the offer, including the number of Shares that such person shall be entitled to purchase, the price to be paid, if any (which shall be as
determined by the Administrator, subject to Applicable Laws, including any applicable securities laws), and the time within which such person must accept such offer. The permissible consideration for Restricted Stock, if any, shall be determined by
the Administrator and shall be the same as is set forth in Section 7(b)(ii) above with respect to exercise of Options. The offer to purchase Shares shall be accepted by execution of an Award Agreement in the form determined by the
Administrator. 
 (b)    Repurchase Option. 

(i)    General. Unless the Administrator determines otherwise, the Restricted Stock Award Agreement
shall grant the Company a repurchase option exercisable upon the voluntary or involuntary termination of the Participant’s Continuous Service Status for any reason (including death or Disability) at a purchase price for Shares equal to the
lesser of (A) the original purchase price paid by the purchaser to the Company for such Shares and (B) the Fair Market Value of such Shares, and may be paid by cancellation of any indebtedness of the purchaser to the Company. The
repurchase option shall lapse at such rate as the Administrator may determine. 
 (ii)    Leave of
Absence. The Administrator shall have the discretion to determine whether and to what extent the lapsing of Company repurchase rights shall be tolled during any leave of absence; provided, however, that in the absence of such
determination, such lapsing shall be tolled during any leave (unless otherwise required by Applicable Laws). Notwithstanding the foregoing, in the event of military leave, the lapsing of Company repurchase rights shall toll during any unpaid portion
of such leave, provided that, upon a Participant’s 

  
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returning from military leave (under conditions that would entitle him or her to protection upon such return under the Uniform Services Employment and Reemployment Rights Act), he or she shall be
given vesting credit with respect to Shares purchased pursuant to the Restricted Stock Award Agreement to the same extent as would have applied had the Participant continued to provide services to the Company (or any Parent, Subsidiary or Affiliate,
if applicable) throughout the leave on the same terms as he or she was providing services immediately prior to such leave. 

(c)    Other Provisions. The Restricted Stock Award Agreement shall contain such other terms,
provisions and conditions not inconsistent with the Plan as may be determined by the Administrator in its sole discretion. In addition, the provisions of Restricted Stock Award Agreements need not be the same with respect to each Participant. Each
Restricted Stock grant shall be subject to the conditions set forth in this Plan and to such other conditions not inconsistent with the Plan as determined by the Committee and may be reflected in the applicable Award Agreement. The Committee shall
establish restrictions applicable to such Restricted Stock, including the time or times at which Restricted Stock shall be granted or become vested. The Committee may in its sole discretion accelerate the vesting and/or the lapse of any or all of
the restrictions on the Restricted Stock which acceleration shall not affect any other terms and conditions of such Awards. 

(d)    Rights as a Holder of Capital Stock. Subject to the terms and conditions of the Stockholders
Agreement and the Registration Rights Agreement, as applicable, once the Restricted Stock is purchased, the Participant shall have the rights equivalent to those of a holder of capital stock, and shall be a record holder when his or her purchase and
the issuance of the Shares is entered upon the records of the duly authorized transfer agent of the Company. No adjustment will be made for a dividend or other right for which the record date is prior to the date the Restricted Stock is purchased,
except as provided in Section 10 below and subject to Section 15 below. 
 9.    Taxes.

 (a)    As a condition of the grant, vesting and exercise of an Award, the Participant (or in the case of the
Participant’s death or a permitted transferee, the person holding or exercising the Award) shall make such arrangements as the Administrator may require for the satisfaction of any applicable U.S. federal, state, local or foreign tax,
withholding, and any other required deductions or payments that may arise in connection with such Award. The Company shall not be required to issue any Shares under the Plan until such obligations are satisfied. 

(b)    The Administrator may, to the extent permitted under Applicable Laws, permit a Participant (or in the case of the
Participant’s death or a permitted transferee, the person holding or exercising the Award) to satisfy all or part of his or her tax, withholding, or any other required deductions or payments by Cashless Exercise or by surrendering Shares
(either directly or by stock attestation) that he or she previously acquired and for which the Participant has good title free and clear of any liens and encumbrances; provided that, unless specifically permitted by the Company, any such Cashless
Exercise must be an approved broker-assisted Cashless Exercise or the Shares withheld in the Cashless Exercise must be limited to avoid financial accounting charges under applicable accounting guidance and any such surrendered Shares must have been
previously held for any minimum duration required to avoid financial accounting charges under 

  
 -12- 

 
applicable accounting guidance. Any payment of taxes by surrendering Shares to the Company may be subject to restrictions, including, but not limited to, any restrictions required by rules of the
Securities and Exchange Commission. 
 (c)    Although the Company does not guarantee the particular tax treatment of an
Award granted under the Plan, Awards granted under the Plan are intended to comply with, or be exempt from, the applicable requirements of Code Section 409A and the Plan and any Award Agreement hereunder shall be limited, construed and
interpreted in accordance with such intent. To the extent that any Award granted under the Plan constitutes “non-qualified deferred compensation” pursuant to Code Section 409A, it shall be paid
in a manner that will comply with or be exempt from Code Section 409A. In no event whatsoever shall the Company be liable for any additional tax, interest or penalties that may be imposed on an Award by Code Section 409A or any damages for
failing to comply with Code Section 409A. 
 10.    Adjustments Upon Changes in Capitalization, Merger or
Certain Other Transactions. 
 (a)    Changes in Capitalization. Subject to any
action required under Applicable Laws by the holders of capital stock of the Company, (i) the numbers and class of Shares or other stock or securities: (x) available for future Awards under Section 3 above and (y) covered by each
outstanding Award, (ii) the exercise price per Share of each such outstanding Option, and (iii) any repurchase price per Share applicable to Shares issued pursuant to any Award, shall be automatically proportionately adjusted in the event
of a stock split, reverse stock split, stock dividend, combination, consolidation, reclassification of the Shares or subdivision of the Shares. In the event of any increase or decrease in the number of issued Shares effected without receipt of
consideration by the Company, a declaration of an extraordinary dividend with respect to the Shares payable in a form other than Shares in an amount that has a material effect on the Fair Market Value, a recapitalization (including a
recapitalization through a large nonrecurring cash dividend), a rights offering, a reorganization, merger, a spin-off, split-up, change in corporate structure or a
similar occurrence, the Administrator shall make appropriate adjustments, in its discretion, in one or more of (i) the numbers and class of Shares or other stock or securities: (x) available for future Awards under Section 3 above and
(y) covered by each outstanding Award, (ii) the exercise price per Share of each outstanding Option and (iii) any repurchase price per Share applicable to Shares issued pursuant to any Award, and any such adjustment by the
Administrator shall be made in the Administrator’s sole and absolute discretion and shall be final, binding and conclusive. Except as expressly provided herein, no issuance by the Company of shares of stock of any class, or securities
convertible into shares of stock of any class, shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of Shares subject to an Award. If, by reason of a transaction described in this Section 10(a) or
an adjustment pursuant to this Section 10(a), a Participant’s Award agreement or agreement related to any Optioned Stock or Restricted Stock covers additional or different shares of stock or securities, then such additional or different
shares, and the Award agreement or agreement related to the Optioned Stock or Restricted Stock in respect thereof, shall be subject to all of the terms, conditions and restrictions which were applicable to the Award, Optioned Stock and Restricted
Stock prior to such adjustment. 

  
 -13- 

 (b)    Dissolution or Liquidation. In the event of the
dissolution or liquidation of the Company, each Award will terminate immediately prior to the consummation of such action, unless otherwise determined by the Administrator. 

(c)    Corporate Transactions. In the event of (i) a transfer of all or substantially all of the
Company’s assets, (ii) a merger, consolidation or other capital reorganization or business combination transaction of the Company with or into another corporation, entity or person, or (iii) the consummation of a transaction, or
series of related transactions, in which any “person” (as such term is used in Sections 13(d) and 14(d) of the Exchange Act) becomes the “beneficial owner” (as defined in Rule 13d-3 of the
Exchange Act), directly or indirectly, of more than 50% of the Company’s then outstanding capital stock (a “Corporate Transaction”), each outstanding Award (vested or unvested) will be treated as the Administrator determines
(subject to the last sentence of this paragraph), which determination may be made without the consent of any Participant and need not treat all outstanding Awards (or portion thereof) in an identical manner. Such determination, without the consent
of any Participant, may provide (without limitation) for one or more of the following in the event of a Corporate Transaction: (A) the continuation of such outstanding Awards by the Company (if the Company is the surviving corporation); (B) the
assumption of such outstanding Awards by the surviving corporation or its parent; (C) the substitution by the surviving corporation or its parent of new options or equity awards for such Awards; (D) the cancellation of such Awards and a
payment to the Participants equal to the excess of (1) the Fair Market Value of the Shares subject to such Awards as of the closing date of such Corporate Transaction over (2) the exercise price or purchase price for the Shares to be
issued pursuant to the exercise of such Awards (such payment shall be made in the form of cash, cash equivalents and/or securities of the surviving corporation or its parent with a Fair Market Value equal to the required amount; if the exercise
price or purchase price per Share of the Shares to be issued pursuant to the exercise of such Awards exceeds the Fair Market Value per Share of such Shares, as of the closing date of the Corporate Transaction, then such Awards may be cancelled
without making a payment to the Participants); or (E) the opportunity for Participants to exercise the Options prior to the occurrence of the Corporate Transaction and the termination (for no consideration) upon the consummation of such
Corporate Transaction of any Options not exercised prior thereto. 
 (d)    Notwithstanding anything herein to the
contrary, (i) any adjustments made pursuant to this Section 10 to Awards that are considered “non-qualified deferred compensation” within the meaning of Code Section 409A shall be made
in a manner intended to comply with the requirements of Code Section 409A; and (ii) any adjustments made pursuant to this Section 10 to Awards that are not considered “non-qualified
deferred compensation” subject to Code Section 409A shall be made in a manner intended to ensure that after such adjustment, the Awards either (A) continue not to be subject to Code Section 409A or (B) comply with the
requirements of Code Section 409A. 
 11.    Non-Transferability of
Awards. 
 (a)    General. Except as set forth in this Section 11 and subject to
the terms and conditions of the Stockholders Agreement and the Registration Rights Agreement, as applicable, Awards may not be sold, pledged, assigned, hypothecated, transferred or disposed of in any manner other than by will or by the laws of
descent or distribution. The designation of a 

  
 -14- 

 
beneficiary by a Participant will not constitute a transfer. Subject to the terms and conditions of the Stockholders Agreement and the Registration Rights Agreement, as applicable, an Option may
be exercised, during the lifetime of the holder of the Option, only by such holder or a transferee permitted by this Section 11. 

(b)    Limited Transferability Rights. Notwithstanding anything else in this Section 11 and
subject to the terms and conditions of the Stockholders Agreement and the Registration Rights Agreement, as applicable, the Administrator may in its sole discretion grant Nonstatutory Stock Options that may be transferred by instrument to an inter
vivos or testamentary trust in which the Options are to be passed to beneficiaries upon the death of the trustor (settlor) or by gift to Family Members. Further, beginning with (i) the period when the Company begins to rely on the exemption
described in Rule 12h-1(f)(1) promulgated under the Exchange Act, as determined by the Board in its sole discretion, and (ii) ending on the earlier of (A) the date when the Company ceases to rely on
such exemption, as determined by the Board in its sole discretion, or (B) the date when the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, an Option, or prior to exercise, the Shares
subject to the Option, may not be pledged, hypothecated or otherwise transferred or disposed of, in any manner, including by entering into any short position, any “put equivalent position” or any “call equivalent position” (as
defined in Rule 16a-1(h) and Rule 16a-1(b) of the Exchange Act, respectively), other than to (i) persons who are Family Members through gifts or domestic relations
orders, or (ii) to an executor or guardian of the Participant upon the death or disability of the Participant. Notwithstanding the foregoing sentence, the Board, in its sole discretion, may permit transfers of Nonstatutory Stock Options to the
Company or in connection with a Corporate Transaction or other acquisition transactions involving the Company to the extent permitted by Rule 12h-1(f). 

12.    Time of Granting Awards. The date of grant of an Award shall, for all purposes, be the date on
which the Administrator makes the determination granting such Award, or such other date as is determined by the Administrator. 

13.    Amendment and Termination of the Plan. The Board may at any time amend or terminate the Plan,
but no amendment or termination shall be made that would materially and adversely affect the rights of any Participant under any outstanding Award, without his or her consent. In addition, to the extent necessary and desirable to comply with
Applicable Laws, the Company shall obtain the approval of holders of capital stock with respect to any Plan amendment in such a manner and to such a degree as required. 

14.    Conditions Upon Issuance of Shares. Notwithstanding any other provision of the Plan or any
agreement entered into by the Company pursuant to the Plan, the Company shall not be obligated, and shall have no liability for failure, to issue or deliver any Shares under the Plan unless such issuance or delivery would comply with Applicable
Laws, with such compliance determined by the Company in consultation with its legal counsel. As a condition to the exercise of any Option or purchase of any Restricted Stock, the Company may require the person exercising the Option or purchasing the
Restricted Stock to represent and warrant at the time of any such exercise or purchase that the Shares are being purchased only for investment and without any present intention to sell or distribute such Shares if, in the opinion of counsel for the
Company, such a representation is advisable or required by Applicable Laws. Shares issued upon exercise of Options or purchase of Restricted Stock prior to the date, if ever, on which the Common Stock

  
 -15- 

 
becomes a Listed Security shall be subject to a right of first refusal in favor of the Company pursuant to which the Participant will be required to offer Shares to the Company before selling or
transferring them to any third party on such terms and subject to such conditions as is reflected in the applicable Option Agreement or Restricted Stock Award Agreement. Without limiting the foregoing, as a condition to the grant of any Award or the
delivery of any Shares upon the vesting or exercise of any Award, the Company shall have the right to require that the Participant become party to the Stockholders Agreement and/or the Registration Rights Agreement, as applicable. 

15.    Rights as Stockholders. The holder of an Option or other Award shall not be deemed for any purpose,
nor have any of the rights or privileges of, a stockholder of the Company with respect to any Shares purchasable upon the exercise of any part of an Option or deliverable with respect to such other Award unless, until and to the extent that
(i) such holder has signed a joinder to the Stockholders Agreement designated by the Company (in the form attached to such Stockholders Agreement), (ii) in the case of an Option, such Option shall have been exercised pursuant to its terms,
(iii) the Company shall have issued and delivered such Shares to such holder and (iv) the holder’s name shall have been entered as a stockholder of record with respect to such Shares on the books of the Company. 

16.    Beneficiaries. If permitted by the Company, a Participant may designate one or more
beneficiaries with respect to an Award by timely filing the prescribed form with the Company. A beneficiary designation may be changed by filing the prescribed form with the Company at any time before the Participant’s death. Except as
otherwise provided in an Award Agreement, if no beneficiary was designated or if no designated beneficiary survives the Participant, then after a Participant’s death any vested Award(s) shall be transferred or distributed to the
Participant’s estate or to any person who has the right to acquire the Award by bequest or inheritance. 

17.    Approval of Holders of Capital Stock. If required by Applicable Laws, continuance of the Plan
shall be subject to approval by the holders of capital stock of the Company within 12 months before or after the date the Plan is adopted or, to the extent required by Applicable Laws, any date the Plan is amended. Such approval shall be obtained in
the manner and to the degree required under Applicable Laws. 
 18.    Addenda. The Administrator
may approve such addenda to the Plan as it may consider necessary or appropriate for the purpose of granting Awards to Employees or Consultants, which Awards may contain such terms and conditions as the Administrator deems necessary or appropriate
to accommodate differences in local law, tax policy or custom, which may deviate from the terms and conditions set forth in this Plan. The terms of any such addenda shall supersede the terms of the Plan to the extent necessary to accommodate such
differences but shall not otherwise affect the terms of the Plan as in effect for any other purpose. 

19.    Information to Holders of Options. In the event the Company is relying on the exemption
provided by Rule 12h-1(f) under the Exchange Act, then to the extent required, the Company shall provide the information described in Rule 701(e)(3), (4) and (5) of the Securities Act of 1933, as amended,
to all holders of Options in accordance with the requirements thereunder until such time as the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act. The Company may request that holders of Options
agree to keep the 

  
 -16- 

 
information to be provided pursuant to this Section confidential. If the holder does not agree to keep the information to be provided pursuant to this Section confidential, then the Company will
not be required to provide the information unless otherwise required pursuant to Rule 12h-1(f)(1) of the Exchange Act. 

20.    No Right to Continued Employment. The grant of an Award in any year shall not give the Participant
any right to similar grants in future years, any right to continue such Participant’s employment or service relationship with the Company or its Affiliates, or, until Shares are issued, any rights as a stockholder of the Company. All
Participant shall remain subject to discharge to the same extent as if the Plan were not in effect. 
 21.    No
Right to Company Assets. No Participant, and no beneficiary or other persons claiming under or through the Participant, shall have any right, title or interest by reason of any Award to any particular assets of the Company or Affiliates of
the Company, or any Shares allocated or reserved for the purposes of the Plan or subject to any Award except as set forth herein. The Company shall not be required to establish any fund or make any other segregation of assets to assure satisfaction
of the Company’s obligations under the Plan. 
 22.    Governing Law. The Plan and Award grants
hereunder shall be governed by the laws of the State of Delaware. The Plan and Award grants hereunder, and the obligation of the Company to sell and deliver Shares under such Awards, shall be subject to all applicable laws, rules, and regulations,
whether the United States or any other country, state or subdivision thereof having jurisdiction over the Company and the Participant, including the United States Securities Act of 1933, and to such approvals by any governmental agencies or national
securities exchanges as may be required. 
 23.    Severability. If any provision of the Plan or any Award
Agreement is or becomes or is deemed to be invalid, illegal, or unenforceable in any jurisdiction or as to any person or Award, or would disqualify the Plan or any Award under any law deemed applicable by the Committee, such provision shall be
construed or deemed amended to conform to the applicable laws, or if it cannot be construed or deemed amended without, in the determination of the Committee, materially altering the intent of the Plan or the Award, such provision shall be stricken
as to such jurisdiction, person or Award and the remainder of the Plan and any such Award shall remain in full force and effect. 

24.    Successors. The obligations of the Company under the Plan shall be binding upon any successor
corporation or organization resulting from the merger, consolidation or other reorganization of the Company, or upon any successor corporation or organization succeeding to substantially all of the assets and business of the Company. 

25.    Dispute Resolution. All disputes, claims, or controversies arising out of or relating to this
Plan, any Awards granted hereunder or any other agreement executed and delivered pursuant to this Plan, or the negotiation, validity or performance hereof and thereof or the transactions contemplated hereby and thereby, that are not resolved by
mutual agreement shall be resolved solely and exclusively by binding arbitration to be conducted before J.A.M.S./Endispute, Inc. (“JAMS”) or its successor. The parties understand and agree that this arbitration provision shall apply
equally to claims of fraud or fraud in the inducement. The arbitration shall be held in Chicago, Illinois before a single arbitrator and shall be conducted in accordance with the rules and regulations promulgated by JAMS unless specifically modified
herein. 

  
 -17- 

 The parties covenant and agree that the arbitration shall commence within one hundred twenty (120) days of
the date on which a written demand for arbitration is filed by any party hereto. In connection with the arbitration proceeding, the arbitrator shall have the power to order the production of documents by each party and any third-party witnesses. In
addition, each party may take up to three depositions as of right, and the arbitrator may in his or her discretion allow additional depositions upon good cause shown by the moving party. However, the arbitrator shall not have the power to order the
answering of interrogatories or the response to requests for admission. In connection with any arbitration, each party shall provide to the other, no later than fourteen (14) business days before the date of the arbitration, the identity of all
persons that may testify at the arbitration, a copy of all documents that may be introduced at the arbitration or considered or used by a party’s witness or expert, and a summary of the expert’s opinions and the basis for said opinions.
The arbitrator’s decision and award shall be made and delivered within sixty (60) days of the conclusion of the arbitration. The arbitrator’s decision shall set forth a reasoned basis for any award of damages or finding of liability.
The arbitrator shall not have power to award damages in excess of actual compensatory damages and shall not multiply actual damages or award punitive damages or any other damages that are specifically excluded under this Plan, and each party hereby
irrevocably waives any claim to such damages. 
 The parties covenant and agree that they will participate in the arbitration in good faith and that they
will share equally its costs, except as otherwise provided herein. The arbitrator may in his or her discretion assess costs and expenses (including the reasonable legal fees and expenses of the prevailing party) against any party to a proceeding.
Any party unsuccessfully refusing to comply with an order of the arbitrators shall be liable for costs and expenses, including attorneys’ fees, incurred by the other party in enforcing the award. This Section 25 applies equally to requests
for temporary, preliminary or permanent injunctive relief, except that in the case of temporary or preliminary injunctive relief any party may proceed in court without prior arbitration for the limited purpose of avoiding immediate and irreparable
harm. The provisions of this Section 25 shall be enforceable in any court of competent jurisdiction. 
 Subject to the second sentence of the
immediately preceding paragraph, the parties shall bear their own attorneys’ fees, costs and expenses in connection with the arbitration. The parties will share equally in the fees and expenses charged by JAMS. 

Each of the parties hereto irrevocably and unconditionally consents to the exclusive jurisdiction of JAMS to resolve all disputes, claims or
controversies arising out of or relating to this Plan, any Awards granted hereunder or any other agreement executed and delivered pursuant to this Plan or the negotiation, validity or performance hereof and thereof or the transactions contemplated
hereby and thereby and further consents to the jurisdiction of the courts of Chicago, Illinois for the purposes of enforcing the arbitration provisions of this Section 25 of this Plan. Each party further irrevocably waives any objection to
proceeding before JAMS based upon lack of personal jurisdiction or to the laying of venue and further irrevocably and unconditionally waives and agrees not to make a claim in any court that arbitration before JAMS has been brought in an inconvenient
forum. Each of the parties hereto hereby consents to service of process by registered mail at the address to which notices are to be given. Each of the parties hereto agrees that its or his submission to jurisdiction and its or his consent to
service of process by mail is made for the express benefit of the other parties hereto. 

  
 -18- 

 ADDENDUM A 

Twist Bioscience Corporation 2013 Stock Plan 

(California Participants) 

Prior to the date, if ever, on which the Common Stock becomes a Listed Security and/or the Company is subject to the reporting requirements of
the Exchange Act, the terms set forth herein shall apply to Awards issued to California Participants. All capitalized terms used herein but not otherwise defined shall have the respective meanings set forth in the Plan. 

1.    The following rules shall apply to any Option in the event of termination of the Participant’s Continuous
Service Status: 
 (a)    If such termination was for reasons other than death, “Permanent Disability” (as
defined below), or Cause, the Participant shall have at least 30 days (or such greater time period as may be provided in the Plan or Option Agreement) after the date of such termination to exercise his or her Option to the extent the Participant is
entitled to exercise on his or her termination date, provided that in no event shall the Option be exercisable after the expiration of the term as set forth in the Option Agreement. 

(b)    If such termination was due to death or Permanent Disability, the Participant shall have at least 6 months (or such
greater time period as may be provided in the Plan or Option Agreement) after the date of such termination to exercise his or her Option to the extent the Participant is entitled to exercise on his or her termination date, provided that in no event
shall the Option be exercisable after the expiration of the term as set forth in the Option Agreement. 
 “Permanent
Disability” for purposes of this Addendum shall mean the inability of the Participant, in the opinion of a qualified physician acceptable to the Company, to perform the major duties of the Participant’s position with the Company or any
Parent or Subsidiary because of the sickness or injury of the Participant. 
 2.    Notwithstanding anything to the
contrary in Section 10(a) of the Plan, the Administrator shall in any event make such adjustments as may be required by Section 25102(o) of the California Corporations Code. 

3.    Notwithstanding anything stated herein to the contrary, no Option shall be exercisable on or after the 10th
anniversary of the date of grant and any Award agreement shall terminate on or before the 10th anniversary of the date of grant. 

4.    The Company shall furnish summary financial information (audited or unaudited) of the Company’s financial
condition and results of operations, consistent with the requirements of Applicable Laws, at least annually to each California Participant during the period such Participant has one or more Awards outstanding, and in the case of an individual who
acquired Shares pursuant to the Plan, during the period such Participant owns such Shares; provided, however, the Company shall not be required to provide such information if (i) the issuance is limited to key persons whose duties in connection
with the Company assure their access to equivalent information or (ii) the Plan or any agreement complies with all conditions of Rule 701 

 
of the Securities Act of 1933, as amended; provided that for purposes of determining such compliance, any registered domestic partner shall be considered a “family member” as that term
is defined in Rule 701. 

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

NOTICE OF STOCK OPTION GRANT 

[Optionee Name] 
 [Optionee Address Line 1] 

[Optionee Address Line 2] 
 You have been granted
an Option to purchase Shares of Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), as provided in this Notice of Stock Option Grant (this “Notice”) and subject to the terms and
conditions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) and the Stock Option Agreement attached hereto, both of which are made a part of this Notice. Unless otherwise defined in this Notice, capitalized terms
used but not defined in this Notice shall have the meanings defined in the Plan. 
  

			
	Date of Grant:	  	                    
		
	Total Number of Shares:	  	                    
		
	Exercise Price per Share:	  	$                  
		
	Designation of Option:	  	          Incentive Stock Option

 
          Nonstatutory Stock
Option

		
	Expiration Date:	  	                    
		
	Vesting Commencement Date:	  	                    
		
	Vesting/Exercise Schedule:	  	So long as your Continuous Service Status does not terminate, the Shares underlying this Option shall vest and become exercisable in accordance with the following schedule: [25% of the Total Number of Shares shall vest and become
exercisable on the one year anniversary of the Vesting Commencement Date, and 1/48th of the Total Number of Shares shall vest and become exercisable on the same day of each month thereafter (and if there is no corresponding day, on the last day of
the month)].
		
	Termination Period:	  	You may exercise this Option for 3 month(s) after termination of your Continuous Service Status, except as otherwise provided in Section 5 of the Stock Option Agreement (but in no event later than the Expiration Date). You
are responsible for keeping track of these exercise periods following the termination of your Continuous Service Status for any reason. The Company will not provide further notice of such periods.

 By your signature and the signature of the Company’s representative below, you and the
Company agree that this Option is granted under and governed by the terms and conditions of this Notice, the Plan and the Stock Option Agreement. Further, as a condition to the grant of this Option and/or the delivery of any Shares upon the vesting
or exercise of this Option, the Company shall have the right to require that you become party to the Stockholders Agreement and/or the Registration Rights Agreement. 

In addition, you agree and acknowledge that your rights to any Shares underlying this Option will be earned only as you provide services to
the Company over time, that the grant of this Option is not as consideration for services you rendered to the Company prior to your date of hire, and that nothing in this Notice or the attached documents confers upon you any right to continue your
employment or consulting relationship with the Company for any period of time, nor does it interfere in any way with your right or the Company’s right to terminate that relationship at any time, for any reason, with or without cause. For
purposes of this paragraph, the term “Company” will be interpreted to include any Parent, Subsidiary or Affiliate. 
  

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	
                     

		 	(Signature)
	Name:	 	
                     
                    

	Title:	 	
                     
                    

	
	 OPTIONEE:
  

	(PRINT NAME)
	
	
                     
                    

	(Signature)

 
			
		
	Address:	 	
                     

		 	
                  
   

  
 -2- 

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

STOCK OPTION AGREEMENT 

1.    Grant of Option. Twist Bioscience Corporation, a Delaware corporation (the
“Company”), hereby grants to                      (“Optionee”), an option (the “Option”) to
purchase the total number of shares of Common Stock (the “Shares”) set forth in the Notice of Stock Option Grant (the “Notice”), at the exercise price per Share set forth in the Notice (the “Exercise
Price”) subject to the terms, definitions and provisions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) adopted by the Company, which is incorporated in this Stock Option Agreement (this
“Agreement”) by reference. Unless otherwise defined in this Agreement, the terms used in this Agreement or the Notice shall have the meanings defined in the Plan. 

2.    Designation of Option. This Option is intended to be an Incentive Stock Option as defined in
Section 422 of the Code only to the extent so designated in the Notice, and to the extent it is not so designated, or to the extent this Option does not or ceases to qualify as an Incentive Stock Option, it shall be treated as a Nonstatutory
Stock Option. 
 Notwithstanding the above, if designated as an Incentive Stock Option, in the event that the Shares subject to this Option
(and all other incentive stock options granted to Optionee by the Company or any Parent or Subsidiary, including under other plans) that first become exercisable in any calendar year have an aggregate Fair Market Value (determined for each Share as
of the date of grant of the option covering such Share) in excess of $100,000, this Option, to the extent the value thereof is in excess of $100,000, shall be treated as a Nonstatutory Stock Option, in accordance with Section 7(c) of the Plan.

 3.    Exercise of Option. This Option shall be exercisable during its term in accordance with
the Vesting/Exercise Schedule set out in the Notice and with the provisions of Section 7(c) of the Plan as follows: 

(a)    Right to Exercise. 

(i)    This Option may not be exercised for a fraction of a share. 

(ii)    In the event of Optionee’s death, Disability or other termination of Continuous Service Status, the
exercisability of this Option is governed by Section 5 below, subject to the limitations contained in this Section 3. 

(iii)    In no event may this Option be exercised after the Expiration Date set forth in the Notice. 

 (b)    Method of Exercise. 

(i)    This Option shall be exercisable by execution and delivery of the Exercise Agreement attached hereto as
Exhibit A or of any other form of written notice approved for such purpose by the Company which shall state Optionee’s election to exercise this Option, the number of Shares in respect of which this Option is being exercised, and
such other representations and agreements as to the holder’s investment intent with respect to such Shares as may be required by the Company pursuant to the provisions of the Plan. Such written notice shall be signed by Optionee and shall be
delivered to the Company by such means as are determined by the Company in its discretion to constitute adequate delivery. The written notice shall be accompanied by payment of the aggregate Exercise Price for the purchased Shares. 

(ii)    As a condition to the exercise of this Option and subject to Section 9 of the Plan, Optionee agrees to make
adequate provision for federal, state or other applicable tax, withholding, required deductions or other payments, if any, which arise upon the grant, vesting or exercise of this Option, or disposition of Shares, whether by withholding, direct
payment to the Company, or otherwise, as determined by the Company in its sole discretion. 
 (iii)    The Company is
not obligated, and will have no liability for failure, to issue or deliver any Shares upon exercise of this Option unless such issuance or delivery would comply with the Applicable Laws, with such compliance determined by the Company in consultation
with its legal counsel. This Option may not be exercised until such time as the Plan has been approved by the holders of capital stock of the Company, or if the issuance of such Shares upon such exercise or the method of payment of consideration for
such Shares would constitute a violation of any Applicable Laws, including any applicable U.S. federal or state securities laws or any other law or regulation, including any rule under Part 221 of Title 12 of the Code of Federal
Regulations as promulgated by the Federal Reserve Board. As a condition to the exercise of this Option, the Company may require Optionee to make any representation and warranty to the Company as may be required by the Applicable Laws. Assuming such
compliance, for income tax purposes the Shares shall be considered transferred to Optionee on the date on which this Option is exercised with respect to such Shares. 

(iv)    Subject to compliance with Applicable Laws, this Option shall be deemed to be exercised upon receipt by the
Company of the appropriate written notice of exercise accompanied by the Exercise Price and the satisfaction of any applicable obligations described in Section 3(b)(ii) above. 

4.    Method of Payment. Payment of the Exercise Price shall be by cash or check or, following the
initial public offering of the Company’s Common Stock, by Cashless Exercise pursuant to which the Optionee delivers an irrevocable direction to a securities broker (on a form prescribed by the Company and according to a procedure established by
the Company). 
 5.    Termination of Relationship. Following the date of termination of
Optionee’s Continuous Service Status for any reason (the “Termination Date”), Optionee may exercise this Option only as set forth in the Notice and this Section 5. If Optionee does not exercise this Option within the
Termination Period set forth in the Notice or the termination periods set forth below, this Option shall terminate in its entirety. In no event, may any Option be exercised after the Expiration Date of this Option as set forth in the Notice. 

  
 -2- 

 (a)    General Termination. In the event of termination
of Optionee’s Continuous Service Status other than as a result of Optionee’s Disability or death or Optionee’s termination by the Company for Cause, Optionee may, to the extent Optionee is vested in the Optioned Stock at the date of
such termination, exercise this Option during the Termination Period set forth in the Notice (but in no event later than the Expiration Date). 

(b)    Termination upon Disability of Optionee. In the event of termination of Optionee’s
Continuous Service Status as a result of Optionee’s Disability, Optionee may, but only within 12 month(s) following the Termination Date, exercise this Option to the extent Optionee is vested in the Optioned Stock. 

(c)    Death of Optionee. In the event of termination of Optionee’s Continuous Service Status as
a result of Optionee’s death, or in the event of Optionee’s death within 3 month(s) following Optionee’s Termination Date, this Option may be exercised at any time within 12 month(s) following the Termination Date, or if later, 12
month(s) following the date of death (but in each case, in no event later than the Expiration Date) by any beneficiaries designated in accordance with Section 16 of the Plan or, if there are no such beneficiaries, by the Optionee’s estate,
or by a person who acquired the right to exercise the Option by bequest or inheritance, but only to the extent Optionee is vested in this Option. 

(d)    Termination for Cause. In the event of termination of Optionee’s Continuous Service
Status by the Company for Cause, this Option (including any vested portion thereof) shall immediately terminate in its entirety upon first notification to Optionee of such termination by the Company for Cause. If Optionee’s Continuous Service
Status is suspended pending an investigation of whether Optionee’s Continuous Service Status will be terminated by the Company for Cause, all Optionee’s rights under this Option, including the right to exercise this Option, shall be
suspended during the investigation period. 
 6.    Non-Transferability of
Option. This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised during the lifetime of Optionee only by him or her, subject to the terms of the Plan and
the Stockholders Agreement. The terms of this Option shall be binding upon the executors, administrators, heirs, successors and assigns of Optionee. 

7.    Lock-Up Agreement. Without limitation on anything in
the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters in connection with the initial public offering of the Company’s securities registered under the
Securities Act of 1933, as amended, Optionee shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of or
otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the effective date of the relevant registration statement filed under the Securities Act in connection with
the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant registration statement in connection with any other public offering of registrable securities, as such
underwriter shall specify reasonably and in good faith. 

  
 -3- 

 8.    Effect of Agreement. Optionee acknowledges receipt
of a copy of the Plan and represents that he or she is familiar with the terms and provisions thereof (and has had an opportunity to consult counsel regarding the Option terms), and hereby accepts this Option and agrees to be bound by its
contractual terms as set forth herein and in the Plan. Optionee hereby agrees to accept as binding, conclusive and final all decisions and interpretations of the Administrator regarding any questions relating to this Option. In the event of a
conflict between the terms and provisions of the Plan and the terms and provisions of the Notice and this Agreement, the Plan terms and provisions shall prevail. 

9.    Imposition of Other Requirements. The Company reserves the right to impose other requirements
on Optionee’s participation in the Plan, on the Option and on any Award or Shares acquired under the Plan, to the extent the Company determines it is necessary or advisable in order to comply with Applicable Laws or facilitate the
administration of the Plan. Optionee agrees to sign any additional agreements or undertakings that may be necessary to accomplish the foregoing, including, without limitation, the Stockholders Agreement and/or the Registration Rights Agreement.
Furthermore, Optionee acknowledges that the laws of the country in which Optionee is working at the time of grant, vesting and exercise of the Option or the sale of Shares received pursuant to this Agreement (including any rules or regulations
governing securities, foreign exchange, tax, labor, or other matters) may subject Optionee to additional procedural or regulatory requirements that Optionee is and will be solely responsible for and must fulfill. 

10.    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to Optionee’s current or future participation in the Plan by electronic means or to request Optionee’s consent to participate in the Plan by electronic means. By accepting this Option grant, Optionee hereby consents to receive such
documents by electronic delivery and agrees to participate in the Plan through an on-line or electronic system established and maintained by the Company or a third party designated by the Company. 

11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted
only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Plan and the Notice, set forth the entire
agreement and understanding of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the subject matter hereof. 

(c)    Amendments and Waivers. No modification of or amendment to this Agreement, nor any waiver of
any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of that provision as to that or
any other instance. 

  
 -4- 

 (d)    Successors and Assigns. Except as otherwise
provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal representatives.
The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior
written consent of the Company. 
 (e)    Notices. Any notice, demand or request required or
permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or registered mail
with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most recent address
set forth in the Company’s books and records. 
 (f)    Severability. If one or more
provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 
 (g)    Construction. This Agreement is the result of negotiations
between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against
any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed in any number
of counterparts, each of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Code Section 409A. It is intended that the Option comply with or be
exempt from Section 409A of the Code, and this Agreement shall be limited, construed and interpreted in accordance with such intent; provided, that for the avoidance of doubt, this provision shall not be construed to require a gross-up payment in respect of any taxes, interest or penalties imposed on the Optionee as a result of Section 409A of the Code, and by accepting this Option grant, the Optionee agrees and acknowledges that the
Company be held liable for any applicable costs, taxes, or penalties associated with this Option or this Agreement under Code Section 409A or otherwise. 

  
 -5- 

 EXHIBIT A 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EXERCISE AGREEMENT 

This Exercise Agreement (this “Agreement”) is made as of
                    , by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). The purchase
price for the Shares shall be $         per Share, for a total purchase price of $        . 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Purchaser shall not assign, encumber or dispose of any interest in the Shares except in compliance with the Stockholders Agreement.

 (a)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein
will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of the Option Agreement, including, without
limitation, Section 7 of the Option Agreement. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

(b)    Lock-Up Agreement. The
lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 

 4.    Investment and Taxation Representations. In
connection with the purchase of the Shares, Purchaser represents to the Company the following: 
 (a)    Purchaser is
aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment
for Purchaser’s own account only and not with a view to, or for resale in connection with, any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any
present intention to transfer the Shares to any other person or entity. 
 (b)    Purchaser understands that the Shares
have not been registered under the Securities Act by reason of a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

(c)    Purchaser further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the securities. 

(d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act, which, in substance,
permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to
the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the
Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of
securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 4(d), Purchaser acknowledges and agrees to the restrictions set forth in Section 4(e) below. 

(e)    Purchaser further understands that in the event all of the applicable requirements of Rule 144 are not satisfied,
registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not exclusive, the Staff of the Securities and Exchange Commission has
expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption from registration
is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result of Purchaser’s purchase
or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying on the Company for any tax
advice. 

  
 -2- 

 5.    Voting Provisions. As condition precedent to
entering into this Agreement, Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the
Stockholders Agreement, including the restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

6.    Restrictive Legends and Stop-Transfer Orders. 

(A)    Legends. Any certificate or certificates representing the Shares shall bear such
legends as may be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

(b)    Stop-Transfer Notices. Purchaser agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in
its own records. 
 (c)    Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or
other transferee to whom such Shares shall have been so transferred. 
 7.    No Employment Rights.
Nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or
without cause. 
 8.    Waiver of Statutory Information Rights. Optionee acknowledges and
understands that, but for the waiver made herein, Optionee would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s stock ledger, a
list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the Delaware General Corporation Law (any and all
such rights, and any and all such other rights of Optionee as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the general public
pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Optionee hereby unconditionally and irrevocably waives the Inspection Rights, whether such
Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign, transfer, or cause to
be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Optionee in Optionee’s capacity as a stockholder and shall not affect any
rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Optionee under any written agreement with the Company. 

  
 -3- 

 9.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or amendment to this
Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of
that provision as to that or any other instance. 
 (d)    Successors and Assigns. Except as
otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal
representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except
with the prior written consent of the Company. 
 (e)    Notices. Any notice, demand or request
required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or
registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most
recent address set forth in the Company’s books and records. 
 (f)    Severability. If one or
more provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 

  
 -4- 

 (g)    Construction. This Agreement is the result of
negotiations between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor
of or against any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed
in any number of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the
statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or
otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

  
 -5- 

 The parties have executed this Exercise Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

	
	PURCHASER:
	
	  

	(PRINT NAME)
	
	  

	(Signature)

 
			
		
	Address:	 	  

		
		 	  

 
			
		
	Email:	 	  

  
 -6- 

 I,
                    , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

  
 -7- 

 Early Exercise Form 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

NOTICE OF STOCK OPTION GRANT 

[Optionee Name] 
 [Optionee Address Line 1] 

[Optionee Address Line 2] 
 You have been granted
an Option to purchase Shares of Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), as provided in this Notice of Stock Option Grant (this “Notice”) and subject to the terms and
conditions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) and the Stock Option Agreement attached hereto, both of which are made a part of this Notice. Unless otherwise defined in this Notice, capitalized terms
used but not defined in this Notice shall have the meanings defined in the Plan. 
  

			
	Date of Grant:	  	              
		
	Total Number of Shares:	  	              
		
	Exercise Price per Share:	  	$            
		
	Designation of Option:	  	          Incentive Stock Option

 
          Nonstatutory Stock
Option

		
	Expiration Date:	  	              
		
	Vesting Commencement Date:	  	              
		
	Exercise Schedule:	  	The Option is immediately exercisable as to all Shares underlying this Option.
		
	Vesting Schedule:	  	So long as your Continuous Service Status does not terminate, the Shares underlying this Option shall vest in accordance with the following schedule: [25% of the Total Number of Shares shall vest on the one year anniversary of
the Vesting Commencement Date, and 1/48th of the Total Number of Shares shall vest on the same day of each month thereafter (and if there is no corresponding day, on the last day of the month)].
		
	Termination Period:	  	You may exercise this Option for 3 month(s) after termination of your Continuous Service Status, except as otherwise provided in Section 5 of the Stock Option Agreement (but in no event later than the Expiration Date). You
are responsible for keeping track of these exercise periods following the termination of your Continuous Service Status for any reason. The Company will not provide further notice of such periods.

 By your signature and the signature of the Company’s representative below, you and the
Company agree that this Option is granted under and governed by the terms and conditions of this Notice, the Plan and the Stock Option Agreement. Further, as a condition to the grant of this Option and/or the delivery of any Shares upon the vesting
or exercise of this Option, the Company shall have the right to require that you become party to the Stockholders Agreement and/or the Registration Rights Agreement. 

In addition, you agree and acknowledge that your rights to any Shares underlying this Option will be earned only as you provide services to
the Company over time, that the grant of this Option is not as consideration for services you rendered to the Company prior to your date of hire, and that nothing in this Notice or the attached documents confers upon you any right to continue your
employment or consulting relationship with the Company for any period of time, nor does it interfere in any way with your right or the Company’s right to terminate that relationship at any time, for any reason, with or without cause. For
purposes of this paragraph, the term “Company” will be interpreted to include any Parent, Subsidiary or Affiliate. 
  

			
	
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

 
			
	
	OPTIONEE:
	
	  

	(PRINT NAME)
	
	  

	(Signature)

 
			
		
	Address:	 	  

		
		 	  

  
 -2- 

 Early Exercise Form 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

STOCK OPTION AGREEMENT 

1.    Grant of Option. Twist Bioscience Corporation, a Delaware corporation (the
“Company”), hereby grants to                      (“Optionee”), an option (the “Option”) to
purchase the total number of shares of Common Stock (the “Shares”) set forth in the Notice of Stock Option Grant (the “Notice”), at the exercise price per Share set forth in the Notice (the “Exercise
Price”) subject to the terms, definitions and provisions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) adopted by the Company, which is incorporated in this Stock Option Agreement (this
“Agreement”) by reference. Unless otherwise defined in this Agreement, the terms used in this Agreement or the Notice shall have the meanings defined in the Plan. 

2.    Designation of Option. This Option is intended to be an Incentive Stock Option as defined in
Section 422 of the Code only to the extent so designated in the Notice, and to the extent it is not so designated, or to the extent this Option does not or ceases to qualify as an Incentive Stock Option, it shall be treated as a Nonstatutory
Stock Option. 
 Notwithstanding the above, if designated as an Incentive Stock Option, in the event that the Shares subject to this Option
(and all other incentive stock options granted to Optionee by the Company or any Parent or Subsidiary, including under other plans) that first become exercisable in any calendar year have an aggregate Fair Market Value (determined for each Share as
of the date of grant of the option covering such Share) in excess of $100,000, this Option, to the extent the value thereof is in excess of $100,000, shall be treated as a Nonstatutory Stock Option, in accordance with Section 7(c) of the Plan.

 3.    Exercise of Option. This Option shall be exercisable during its term in accordance with
the Exercise Schedule set out in the Notice and with the provisions of Section 7(c) of the Plan as follows: 

(a)    Right to Exercise. 

(i)    This Option may not be exercised for a fraction of a share. 

(ii)    In the event of Optionee’s death, Disability or other termination of Continuous Service Status, the
exercisability of this Option is governed by Section 5 below, subject to the limitations contained in this Section 3. 

(iii)    In no event may this Option be exercised after the Expiration Date set forth in the Notice. 

(b)    Method of Exercise. 

(i)    This Option shall be exercisable by execution and delivery of the Early Exercise Notice and Restricted Stock
Purchase Agreement attached hereto as Exhibit A, the 

 
Exercise Agreement attached hereto as Exhibit B or of any other form of written notice approved for such purpose by the Company which shall state Optionee’s
election to exercise this Option, the number of Shares in respect of which this Option is being exercised, and such other representations and agreements as to the holder’s investment intent with respect to such Shares as may be required by the
Company pursuant to the provisions of the Plan. Such written notice shall be signed by Optionee and shall be delivered to the Company by such means as are determined by the Company in its discretion to constitute adequate delivery. The written
notice shall be accompanied by payment of the aggregate Exercise Price for the purchased Shares. 
 (ii)    As a
condition to the exercise of this Option and subject to Section 9 of the Plan, Optionee agrees to make adequate provision for federal, state or other applicable tax, withholding, required deductions or other payments, if any, which arise upon
the grant, vesting or exercise of this Option, or disposition of Shares, whether by withholding, direct payment to the Company, or otherwise, as determined by the Company in its sole discretion. 

(iii)    The Company is not obligated, and will have no liability for failure, to issue or deliver any Shares upon
exercise of this Option unless such issuance or delivery would comply with the Applicable Laws, with such compliance determined by the Company in consultation with its legal counsel. This Option may not be exercised until such time as the Plan has
been approved by the holders of capital stock of the Company, or if the issuance of such Shares upon such exercise or the method of payment of consideration for such Shares would constitute a violation of any Applicable Laws, including any
applicable U.S. federal or state securities laws or any other law or regulation, including any rule under Part 221 of Title 12 of the Code of Federal Regulations as promulgated by the Federal Reserve Board. As a condition to the exercise
of this Option, the Company may require Optionee to make any representation and warranty to the Company as may be required by the Applicable Laws. Assuming such compliance, for income tax purposes the Shares shall be considered transferred to
Optionee on the date on which this Option is exercised with respect to such Shares. 
 (iv)    Subject to compliance
with Applicable Laws, this Option shall be deemed to be exercised upon receipt by the Company of the appropriate written notice of exercise accompanied by the Exercise Price and the satisfaction of any applicable obligations described in
Section 3(b)(ii) above. 
 4.    Method of Payment. Payment of the Exercise Price shall be by
cash or check or, following the initial public offering of the Company’s Common Stock, by Cashless Exercise pursuant to which the Optionee delivers an irrevocable direction to a securities broker (on a form prescribed by the Company and
according to a procedure established by the Company). 
 5.    Termination of Relationship.
Following the date of termination of Optionee’s Continuous Service Status for any reason (the “Termination Date”), Optionee may exercise this Option only as set forth in the Notice and this Section 5. If Optionee does
not exercise this Option within the Termination Period set forth in the Notice or the termination periods set forth below, this Option shall terminate in its entirety. In no event, may any Option be exercised after the Expiration Date of this Option
as set forth in the Notice. 

  
 -2- 

 (a)    General Termination. In the event of termination
of Optionee’s Continuous Service Status other than as a result of Optionee’s Disability or death or Optionee’s termination by the Company for Cause, Optionee may, to the extent Optionee is vested in the Optioned Stock, exercise this
Option during the Termination Period set forth in the Notice (but in no event later than the Expiration Date). 

(b)    Termination upon Disability of Optionee. In the event of termination of Optionee’s
Continuous Service Status as a result of Optionee’s Disability, Optionee may, but only within 12 month(s) following the Termination Date, exercise this Option to the extent Optionee is vested in the Optioned Stock. 

(c)    Death of Optionee. In the event of termination of Optionee’s Continuous Service Status as
a result of Optionee’s death, or in the event of Optionee’s death within 3 month(s) following Optionee’s Termination Date, this Option may be exercised at any time within 12 month(s) following the Termination Date, or if later, 12
month(s) following the date of death (but in each case, in no event later than the Expiration Date) by any beneficiaries designated in accordance with Section 16 of the Plan or, if there are no such beneficiaries, by the Optionee’s estate,
or by a person who acquired the right to exercise the Option by bequest or inheritance, but only to the extent Optionee is vested in this Option. 

(d)    Termination for Cause. In the event of termination of Optionee’s Continuous Service
Status by the Company for Cause, this Option (including any vested portion thereof) shall immediately terminate in its entirety upon first notification to Optionee of such termination by the Company for Cause. If Optionee’s Continuous Service
Status is suspended pending an investigation of whether Optionee’s Continuous Service Status will be terminated by the Company for Cause, all Optionee’s rights under this Option, including the right to exercise this Option, shall be
suspended during the investigation period. 
 6.    Non-Transferability of
Option. This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised during the lifetime of Optionee only by him or her, subject to the terms of the Plan and
the Stockholders Agreement. The terms of this Option shall be binding upon the executors, administrators, heirs, successors and assigns of Optionee. 

7.    Lock-Up Agreement. Without limitation on anything in
the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters in connection with the initial public offering of the Company’s securities registered under the
Securities Act of 1933, as amended, Optionee shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of or
otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the effective date of the relevant registration statement filed under the Securities Act in connection with
the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant registration statement in connection with any other public offering of registrable securities, as such
underwriter shall specify reasonably and in good faith. 

  
 -3- 

 8.    Effect of Agreement. Optionee acknowledges receipt
of a copy of the Plan and represents that he or she is familiar with the terms and provisions thereof (and has had an opportunity to consult counsel regarding the Option terms), and hereby accepts this Option and agrees to be bound by its
contractual terms as set forth herein and in the Plan. Optionee hereby agrees to accept as binding, conclusive and final all decisions and interpretations of the Administrator regarding any questions relating to this Option. In the event of a
conflict between the terms and provisions of the Plan and the terms and provisions of the Notice and this Agreement, the Plan terms and provisions shall prevail. 

9.    Imposition of Other Requirements. The Company reserves the right to impose other requirements
on Optionee’s participation in the Plan, on the Option and on any Award or Shares acquired under the Plan, to the extent the Company determines it is necessary or advisable in order to comply with Applicable Laws or facilitate the
administration of the Plan. Optionee agrees to sign any additional agreements or undertakings that may be necessary to accomplish the foregoing, including, without limitation, the Stockholders Agreement and/or the Registration Rights Agreement.
Furthermore, Optionee acknowledges that the laws of the country in which Optionee is working at the time of grant, vesting and exercise of the Option or the sale of Shares received pursuant to this Agreement (including any rules or regulations
governing securities, foreign exchange, tax, labor, or other matters) may subject Optionee to additional procedural or regulatory requirements that Optionee is and will be solely responsible for and must fulfill. 

10.    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to Optionee’s current or future participation in the Plan by electronic means or to request Optionee’s consent to participate in the Plan by electronic means. By accepting this Option grant, Optionee hereby consents to receive such
documents by electronic delivery and agrees to participate in the Plan through an on-line or electronic system established and maintained by the Company or a third party designated by the Company. 

11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted
only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Plan and the Notice, set forth the entire
agreement and understanding of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the subject matter hereof. 

(c)    Amendments and Waivers. No modification of or amendment to this Agreement, nor any waiver of
any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of that provision as to that or
any other instance. 

  
 -4- 

 (d)    Successors and Assigns. Except as otherwise
provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal representatives.
The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior
written consent of the Company. 
 (e)    Notices. Any notice, demand or request required or
permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or registered mail
with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most recent address
set forth in the Company’s books and records. 
 (f)    Severability. If one or more
provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 
 (g)    Construction. This Agreement is the result of negotiations
between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against
any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed in any number
of counterparts, each of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Code Section 409A. It is intended that the Option comply with or be
exempt from Section 409A of the Code, and this Agreement shall be limited, construed and interpreted in accordance with such intent; provided, that for the avoidance of doubt, this provision shall not be construed to require a gross-up payment in respect of any taxes, interest or penalties imposed on the Optionee as a result of Section 409A of the Code, and by accepting this Option grant, the Optionee agrees and acknowledges that the
Company be held liable for any applicable costs, taxes, or penalties associated with this Option or this Agreement under Code Section 409A or otherwise. 

  
 -5- 

 EXHIBIT A 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EARLY EXERCISE NOTICE AND RESTRICTED STOCK PURCHASE AGREEMENT 

This Agreement (“Agreement”) is made as of
                     by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). Of these Shares,
Purchaser has elected to purchase                  of those Shares which have become vested as of the date hereof under the Vesting Schedule set forth in the Notice of
Stock Option Grant (the “Vested Shares”) and                  Shares which have not yet vested under such Vesting Schedule (the “Unvested
Shares”). The purchase price for the Shares shall be $         per Share for a total purchase price of $        . The term “Shares” refers to
the purchased Shares and all securities received in connection with the Shares pursuant to stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like, and all
new, substituted or additional securities or other property to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares. 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Purchaser shall not assign, encumber or dispose of any interest in the Shares while the Shares are subject to the Company’s
Repurchase Option (as defined below). After any Shares have been released from such Repurchase Option, Purchaser shall not assign, encumber or dispose of any interest in such Shares except in compliance with the Stockholders Agreement. 

  
 -6- 

 (a)    Repurchase Option. 

(i)    In the event of the voluntary or involuntary termination of Purchaser’s Continuous Service Status with the
Company for any reason (including, without limitation, resignation, death or Disability), with or without Cause, the Company shall upon the date of such termination (the “Termination Date”) have an irrevocable, exclusive option (the
“Repurchase Option”) for a period of 3 months from such date to repurchase all or any portion of the Unvested Shares (as defined below) held by Purchaser as of the Termination Date at the original purchase price per Share (adjusted
for any stock splits, stock dividends and the like) specified in Section 1. As used herein, “Unvested Shares” means Shares that have not yet been released from the Repurchase Option. 

(ii)    Unless the Company notifies Purchaser within 3 months from the Termination Date that it does not intend to
exercise its Repurchase Option with respect to some or all of the Unvested Shares, the Repurchase Option shall be deemed automatically exercised by the Company as of the end of such 3-month period following
such termination, provided that the Company may notify Purchaser that it is exercising its Repurchase Option as of a date prior to the end of such 3-month period. Unless Purchaser is otherwise notified by the
Company pursuant to the preceding sentence that the Company does not intend to exercise its Repurchase Option as to some or all of the Unvested Shares to which it applies at the time of termination, execution of this Agreement by Purchaser
constitutes written notice to Purchaser of the Company’s intention to exercise its Repurchase Option with respect to all Unvested Shares to which such Repurchase Option applies. The Company, at its choice, may satisfy its payment obligation to
Purchaser with respect to exercise of the Repurchase Option by either (A) delivering a check to Purchaser in the amount of the purchase price for the Unvested Shares being repurchased, or (B) in the event Purchaser is indebted to the
Company, canceling an amount of such indebtedness equal to the purchase price for the Unvested Shares being repurchased, or (C) by a combination of (A) and (B) so that the combined payment and cancellation of indebtedness equals such
purchase price. In the event of any deemed automatic exercise of the Repurchase Option pursuant to this Section 3(a)(ii) in which Purchaser is indebted to the Company, such indebtedness equal to the purchase price of the Unvested Shares being
repurchased shall be deemed automatically canceled as of the end of such 3-month period following termination of Purchaser’s employment or consulting relationship unless the Company otherwise satisfies
its payment obligations. As a result of any repurchase of Unvested Shares pursuant to this Section 3(a), the Company shall become the legal and beneficial owner of the Unvested Shares being repurchased and shall have all rights and interest
therein or related thereto, and the Company shall have the right to transfer to its own name the number of Unvested Shares being repurchased by the Company, without further action by Purchaser. 

(iii)    One hundred percent (100%) of the Shares shall initially be subject to the Repurchase Option. The Unvested
Shares shall be released from the Repurchase Option in accordance with the Vesting Schedule set forth in the Notice of Stock Option Grant until all Shares are released from the Repurchase Option; provided, however, that such scheduled releases from
the Repurchase Option shall immediately cease as of the Termination Date. Fractional shares shall be rounded to the nearest whole share. 

  
 -7- 

 (b)    Restrictions Binding on Transferees. All
transferees of Shares or any interest therein will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of
the Option Agreement, including, without limitation, Section 7 of the Option Agreement and, insofar as applicable, the Repurchase Option. In the event the Repurchase Option is deemed exercised by the Company pursuant to Section 3(a)(ii)
hereof, the Company may deem any transferee to have transferred the Shares or interest to Purchaser prior to their purchase by the Company, and payment of the purchase price by the Company to such transferee shall be deemed to satisfy
Purchaser’s obligation to pay such transferee for such Shares or interest, and also to satisfy the Company’s obligation to pay Purchaser for such Shares or interest. Any sale or transfer of the Shares shall be void unless the provisions of
this Agreement are satisfied. 
 (c)    Lock-Up Agreement.
The lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 
 4.    Escrow of Unvested Shares. For purposes of facilitating the enforcement of the
provisions of Section 3(a) above, Purchaser agrees, immediately upon receipt of the stock certificate or, in the case of uncertificated securities, notice of issuance, for the Shares subject to the Repurchase Option, to deliver any such stock
certificate(s), as well as a Stock Power in the form attached to this Agreement as Attachment A executed by Purchaser and by Purchaser’s spouse (if required for transfer), in blank, to the Secretary of the Company, or
the Secretary’s designee, to hold such Shares (and such stock certificate(s), if any) and Stock Power in escrow and to take all such actions and to effectuate all such transfers and/or releases as are required in accordance with the terms of
this Agreement. Purchaser hereby acknowledges that the Secretary of the Company, or the Secretary’s designee, is so appointed as the escrow holder with the foregoing authorities as a material inducement to make this Agreement and that said
appointment is coupled with an interest and is accordingly irrevocable. Purchaser agrees that said escrow holder shall not be liable to any party hereof (or to any other party). The escrow holder may rely upon any letter, notice or other document
executed by any signature purported to be genuine and may resign at any time. Purchaser agrees that if the Secretary of the Company, or the Secretary’s designee, resigns as escrow holder for any or no reason, the Board shall have the power to
appoint a successor to serve as escrow holder pursuant to the terms of this Agreement. 
 5.    Investment and
Taxation Representations. In connection with the purchase of the Shares, Purchaser represents to the Company the following: 

(a)    Purchaser is aware of the Company’s business affairs and financial condition and has acquired sufficient
information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment for Purchaser’s own account only and not with a view to, or for resale in connection with,
any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any present intention to transfer the Shares to any other person or entity. 

(b)    Purchaser understands that the Shares have not been registered under the Securities Act by reason of a specific
exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

  
 -8- 

 (c)    Purchaser further acknowledges and understands that the securities
must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the
securities. 
 (d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act,
which, in substance, permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a
non-public offering subject to the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares
pursuant to Rule 144, which rule requires, among other things, that the Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain
specified time periods, and under certain circumstances, that resales of securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 5(d), Purchaser acknowledges and agrees to the
restrictions set forth in Section 5(e) below. 
 (e)    Purchaser further understands that in the event all of the
applicable requirements of Rule 144 are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not
exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a
substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result of Purchaser’s purchase
or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying on the Company for any tax
advice. 
 6.    Voting Provisions. As condition precedent to entering into this Agreement,
Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the Stockholders Agreement, including the
restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

7.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

  
 -9- 

 (b)    Stop-Transfer Notices. Purchaser agrees that, in
order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make
appropriate notations to the same effect in its own records. 
 (c)    Refusal to Transfer. The
Company shall not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to
vote or pay dividends to any purchaser or other transferee to whom such Shares shall have been so transferred. 

8.    No Employment Rights. Nothing in this Agreement shall affect in any manner whatsoever the right
or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or without cause. 

9.    Section 83(b) Election. 

(a)    Purchaser understands that Section 83(a) of the Internal Revenue Code of 1986, as amended (the
“Code”), taxes as ordinary income for a Nonstatutory Stock Option and as alternative minimum taxable income for an Incentive Stock Option the difference between the amount paid for the Shares and the Fair Market Value of the Shares
as of the date any restrictions on the Shares lapse. In this context, “restriction” means the right of the Company to buy back the Shares pursuant to the Repurchase Option set forth in Section 3(a) of this Agreement. Purchaser
understands that Purchaser may elect to be taxed at the time the Shares are purchased, rather than when and as the Repurchase Option expires, by filing an election under Section 83(b) (an “83(b) Election”) of the Code with the
Internal Revenue Service within 30 days from the date of purchase. Even if the Fair Market Value of the Shares at the time of the execution of this Agreement equals the amount paid for the Shares, the election must be made to avoid income and
alternative minimum tax treatment under Section 83(a) in the future. Purchaser understands that failure to file such an election in a timely manner may result in adverse tax consequences for Purchaser. Purchaser further understands that an
additional copy of such election form should be filed with his or her federal income tax return for the calendar year in which the date of this Agreement falls. Purchaser acknowledges that the foregoing is only a summary of the effect of United
States federal income taxation with respect to purchase of the Shares hereunder, and does not purport to be complete, and is not intended or written to be used, and cannot be used, for the purposes of avoiding taxpayer penalties. Purchaser further
acknowledges that the Company has directed Purchaser to seek independent advice regarding the applicable provisions of the Code, the income tax laws of any municipality, state or foreign country in which Purchaser may reside, and the tax
consequences of Purchaser’s death, and Purchaser has consulted, and has been fully advised by, Purchaser’s own tax advisor regarding such tax laws and tax consequences or has knowingly chosen not to consult such a tax advisor. Purchaser
further acknowledges that neither the Company nor any subsidiary or representative of the Company has made any warranty or representation to Purchaser with respect to the tax consequences of Purchaser’s purchase of the Shares or of the making
or failure to make an 83(b) Election. PURCHASER (AND NOT THE 

  
 -10- 

 
COMPANY, ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR APPROPRIATELY FILING SUCH FORM WITH THE IRS, EVEN IF PURCHASER REQUESTS THE COMPANY, ITS AGENTS OR ANY OTHER PERSON MAKE
THIS FILING ON PURCHASER’S BEHALF. 
 (b)    Purchaser agrees that he or she will execute and deliver to the
Company with this executed Agreement a copy of the Acknowledgment and Statement of Decision Regarding Section 83(b) Election (the “Acknowledgment”) attached hereto as Attachment B. Purchaser further
agrees that he or she will execute and submit with the Acknowledgment a copy of the 83(b) Election attached hereto as Attachment C (for tax purposes in connection with the early exercise of an option) if Purchaser has
indicated in the Acknowledgment his or her decision to make such an election. 
 10.    Waiver of Statutory
Information Rights. Purchaser acknowledges and understands that, but for the waiver made herein, Purchaser would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make
copies and extracts from, the Company’s stock ledger, a list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in
Section 220 of the General Corporation Law of Delaware (any and all such rights, and any and all such other rights of Purchaser as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing,
until the first sale of Common Stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Purchaser hereby
unconditionally and irrevocably waives the Inspection Rights, whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly
commence, voluntarily aid in any way, prosecute, assign, transfer, or cause to be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of
Purchaser in Purchaser’s capacity as a stockholder and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Purchaser
under any written agreement with the Company. 
 11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 

  
 -11- 

 (c)    Amendments and Waivers. No modification of or
amendment to this Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall
constitute a waiver of that provision as to that or any other instance. 
 (d)    Successors and
Assigns. Except as otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under
this Agreement, except with the prior written consent of the Company. 
 (e)    Notices. Any
notice, demand or request required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the
U.S. mail as certified or registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on
the signature page, at the most recent address set forth in the Company’s books and records. 

(f)    Severability. If one or more provisions of this Agreement are held to be unenforceable under
applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this
Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms. 

(g)    Construction. This Agreement is the result of negotiations between and has been reviewed by
each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the parties hereto.

 (h)    Counterparts. This Agreement may be executed in any number of which when so executed and
delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 

  
 -12- 

 (j)    Compliance with Law. If at any the Company or its
counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the statutes, rules or regulations of any
applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or otherwise with respect to Shares, and
the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

  
 -13- 

 Early Exercise Form 

The parties have executed this Early Exercise Notice and Restricted Stock Purchase Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION

 
			
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

 
			
	
	PURCHASER:
	
	  

	(PRINT NAME)
	
	  

	(Signature)	 	

 
			
		
	Address:	 	  

		
		 	  

		
	Email:	 	  

 I,
                    , spouse
of                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	 Spouse of Purchaser (if applicable)

  
 -2- 

 Early Exercise Form 

ATTACHMENT A 

STOCK POWER 
 FOR
VALUE RECEIVED, the undersigned (“Holder”), hereby sells, assigns and transfers unto
                                         
                    (“Transferee”)                 shares
of the Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), standing in Holder’s name on the Company’s books as Certificate No.
CS-                     whether held in certificated or uncertificated form, and does hereby irrevocably
constitute and appoint
                                         to
transfer said stock on the books of the Company with full power of substitution in the premises. 
  

							
	Dated:
                                         
                   	 		 		 	HOLDER:
				
		 		 		 	  

		 		 		 	(PRINT NAME)
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Holder (if applicable)

 This Stock Power may only be used as authorized by the Early Exercise Notice and Restricted Stock Purchase
Agreement between the Holder and the Company, dated                      and the exhibits thereto. 

Instructions: Please do not fill in any blanks other than the signature line. The purpose of this assignment is to enable the
Company to exercise its repurchase option set forth in the Agreement without requiring additional signatures on the part of Holder. 

 Early Exercise Form 

IF YOU WISH TO MAKE A SECTION 83(B) ELECTION, THE FILING OF SUCH ELECTION IS YOUR RESPONSIBILITY. 

THE FORM FOR MAKING THIS SECTION 83(B) ELECTION IS ATTACHED TO THIS AGREEMENT. 

YOU MUST FILE THIS FORM WITHIN 30 DAYS OF PURCHASING THE SHARES. 

YOU (AND NOT THE COMPANY, ANY OF ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR FILING SUCH FORM WITH THE IRS, EVEN IF YOU
REQUEST THE COMPANY, ITS AGENTS OR ANY OTHER PERSON TO MAKE THIS FILING ON YOUR BEHALF AND EVEN IF THE COMPANY, ANY OF ITS AGENTS OR ANY OTHER PERSON HAS PREVIOUSLY MADE THIS FILING ON YOUR BEHALF. 

The election should be filed by mailing a signed election form by certified mail, return receipt requested to the IRS Service Center where you file your tax
returns. See www.irs.gov. 

 Early Exercise Form 

ATTACHMENT B 

ACKNOWLEDGMENT AND STATEMENT OF DECISION 

REGARDING SECTION 83(b) ELECTION 

The undersigned has entered into a stock purchase agreement with Twist Bioscience Corporation, a Delaware corporation (the
“Company”), pursuant to which the undersigned is purchasing                  shares of Common Stock of the Company (the “Shares”). In
connection with the purchase of the Shares, the undersigned hereby represents as follows: 
 1.    The undersigned has
carefully reviewed the stock purchase agreement pursuant to which the undersigned is purchasing the Shares. 
 2.    The
undersigned either [check and complete as applicable]: 
 (a)         has consulted, and has been
fully advised by, the undersigned’s own tax advisor,
                                        , whose
business address is
                                        ,
regarding the federal, state and local tax consequences of purchasing the Shares, and particularly regarding the advisability of making elections pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended (the
“Code”) and pursuant to the corresponding provisions, if any, of applicable state law; or 
 (b)
         has knowingly chosen not to consult such a tax advisor. 
 3.    The
undersigned hereby states that the undersigned has decided [check as applicable]: 
  

	 	(a)	         to make an election pursuant to Section 83(b) of the Code, and is submitting to the Company, together with the undersigned’s executed stock purchase
agreement, an executed form entitled “Election Under Section 83(b) of the Internal Revenue Code of 1986;” or 

  

	 	(b)	         not to make an election pursuant to Section 83(b) of the Code. 

4.    Neither the Company nor any subsidiary or representative of the Company has made any warranty or representation to
the undersigned with respect to the tax consequences of the undersigned’s purchase of the Shares or of the making or failure to make an election pursuant to Section 83(b) of the Code or the corresponding
provisions, if any, of applicable state law. 
  

							
	Dated:
                                         
                   	 		 		 	PURCHASER:
				
		 		 		 	  

		 		 		 	(PRINT NAME)
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Purchaser (if applicable)

 ATTACHMENT C 

ELECTION UNDER SECTION 83(B) 

OF THE INTERNAL REVENUE CODE OF 1986 

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code, to include in taxpayer’s gross
income or alternative minimum taxable income, as applicable, for the current taxable year, the amount of any income that may be taxable to taxpayer in connection with taxpayer’s receipt of the property described below: 

 

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

NAME OF TAXPAYER:                     
NAME OF SPOUSE:                     

ADDRESS:                      

 
 United States 

IDENTIFICATION NO. OF TAXPAYER:
                     
 IDENTIFICATION
NO. OF SPOUSE:                      

TAXABLE YEAR:                      

 

	2.	The property with respect to which the election is made is described as follows: 

                shares of the Common Stock of Twist Bioscience
Corporation, a Delaware corporation (the “Company”). 
  

	3.	The date on which the property was transferred is:                      

 

	4.	The property is subject to the following restrictions: 

 Repurchase option at cost in favor of
the Company upon termination of taxpayer’s employment or consulting relationship. 
  

	5.	The fair market value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms will never lapse, of such property is:
$        . 

  

	6.	The amount (if any) paid for such property: $        . 

 The undersigned has submitted a copy of this statement to the person for whom the services were performed in
connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the services in connection with the transfer of said property. 

The undersigned understands that the foregoing election may not be revoked except with the consent of the Commissioner. 

 

							
	Dated:
                                         
                   	 		 		 	PURCHASER:
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Purchaser (if applicable)

  
 -2- 

 EXHIBIT B 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EXERCISE AGREEMENT 

This Exercise Agreement (this “Agreement”) is made as of
                    , by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                     (the “Option Agreement”). The purchase price
for the Shares shall be $         per Share, for a total purchase price of $        . 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Purchaser shall not assign, encumber or dispose of any interest in the Shares except in compliance with the Stockholders Agreement.

 (a)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein
will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of the Option Agreement, including, without
limitation, Section 7 of the Option Agreement. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

(b)    Lock-Up Agreement. The
lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 

 4.    Investment and Taxation Representations. In
connection with the purchase of the Shares, Purchaser represents to the Company the following: 
 (a)    Purchaser is
aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment
for Purchaser’s own account only and not with a view to, or for resale in connection with, any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any
present intention to transfer the Shares to any other person or entity. 
 (b)    Purchaser understands that the Shares
have not been registered under the Securities Act by reason of a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

(c)    Purchaser further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the securities. 

(d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act, which, in substance,
permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to
the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the
Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of
securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 4(d), Purchaser acknowledges and agrees to the restrictions set forth in Section 4(e) below. 

(e)    Purchaser further understands that in the event all of the applicable requirements of Rule 144 are not satisfied,
registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not exclusive, the Staff of the Securities and Exchange Commission has
expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption from registration
is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result of Purchaser’s purchase
or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying on the Company for any tax
advice. 

  
 -2- 

 5.    Voting Provisions. As condition precedent to
entering into this Agreement, Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the
Stockholders Agreement, including the restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

6.    Restrictive Legends and Stop-Transfer Orders. 

(A)    Legends. Any certificate or certificates representing the Shares shall bear such
legends as may be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

(b)    Stop-Transfer Notices. Purchaser agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in
its own records. 
 (c)    Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or
other transferee to whom such Shares shall have been so transferred. 
 7.    No Employment Rights.
Nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or
without cause. 
 8.    Waiver of Statutory Information Rights. Optionee acknowledges and
understands that, but for the waiver made herein, Optionee would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s stock ledger, a
list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the Delaware General Corporation Law (any and all
such rights, and any and all such other rights of Optionee as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the general public
pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Optionee hereby unconditionally and irrevocably waives the Inspection Rights, whether such
Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign, transfer, or cause to
be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Optionee in Optionee’s capacity as a stockholder and shall not affect any
rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Optionee under any written agreement with the Company. 

  
 -3- 

 9.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or amendment to this
Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of
that provision as to that or any other instance. 
 (d)    Successors and Assigns. Except as
otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal
representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except
with the prior written consent of the Company. 
 (e)    Notices. Any notice, demand or request
required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or
registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most
recent address set forth in the Company’s books and records. 
 (f)    Severability. If one or
more provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 

  
 -4- 

 (g)    Construction. This Agreement is the result of
negotiations between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor
of or against any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed
in any number of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the
statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or
otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

  
 -5- 

 The parties have executed this Exercise Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

	
	PURCHASER:
	
	  

	(PRINT NAME)
	
	  

	(Signature)	 	
		
	Address:	 	  

		
		 	  

		
	Email:	 	  

  
 -6- 

 I,
                    , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

Spouse of Purchaser (if applicable)

  
 -7- 

 Early Exercise Form 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

NOTICE OF STOCK OPTION GRANT 
  

                     

Address:
                                         
                     
  

                       
                                      

You have been granted an Option to purchase Shares of Common Stock of Twist Bioscience Corporation, a Delaware corporation (the
“Company”), as provided in this Notice of Stock Option Grant (this “Notice”) and subject to the terms and conditions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) and the Stock
Option Agreement attached hereto, both of which are made a part of this Notice. Unless otherwise defined in this Notice, capitalized terms used but not defined in this Notice shall have the meanings defined in the Plan. 

 

			
	Date of Grant:	  	                       
		
	Total Number of Shares:	  	                       
		
	Exercise Price per Share:	  	USD $            
		
	Designation of Option:	  	          Incentive Stock Option

         Nonstatutory Stock Option

		
	Expiration Date:	  	                      
		
	Vesting Commencement Date:	  	                      
		
	Exercise Schedule:	  	The Option is immediately exercisable as to all Shares underlying this Option.
		
	Vesting Schedule:	  	So long as your Continuous Service Status does not terminate (and provided that no vesting shall occur following the Termination Date as defined in Section 5 of the Stock Option Agreement unless otherwise determined by the
Company in its sole discretion), the Shares underlying this Option shall vest in accordance with the following schedule: 12/48th of the Total Number of Shares shall vest on the one year
anniversary of the Vesting Commencement Date, and 1/48th of the Total Number of Shares shall vest on the same day of each month thereafter (and if there is no corresponding day, on the last day of
the month).

			
	Termination Period:	  	You may exercise this Option for 3 month(s) after the Termination Date, except as otherwise provided in Section 5 of the Stock Option Agreement (but in no event later than the Expiration Date). You are responsible for
keeping track of these exercise periods following the Termination Date for any reason. The Company will not provide further notice of such periods.

 By your signature and the signature of the Company’s representative below or by otherwise accepting
or exercising this Option, you and the Company agree that this Option is granted under and governed by the terms and conditions of this Notice, the Plan and the Stock Option Agreement (which includes the Country-Specific Addendum). Further, as a
condition to the grant of this Option and/or the delivery of any Shares upon the vesting or exercise of this Option, the Company shall have the right to require that you become party to the Stockholders Agreement and/or the Registration Rights
Agreement. 
 In addition, you agree and acknowledge that your rights to any Shares underlying this Option will vest only as you provide
services to the Company or its Subsidiary or Affiliate over time (pursuant to your employment or engagement by a 3rd-party entity and your assignment by such 3rd-party entity to the Company or its Subsidiary or Affiliate), that the grant of this Option is not as consideration for services you rendered to the Company or its Subsidiary or Affiliate (as
assigned by such 3rd-party as your employer or hiring entity) prior to your date of hire by such entity or your assignment to the Company or any Subsidiary or Affiliate, and that nothing in this
Notice or the attached documents establishes any right to employment nor confers upon you any right to continue in your services to the Company or any Subsidiary or Affiliate for any period of time, nor does it interfere in any way with your right
or your employer or hiring entity’s right to terminate your relationship and any assignment to the Company or its Subsidiary or Affiliate at any time, for any reason, with or without cause, subject to Applicable Laws. 

  
 -2- 

 
			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

 
			
	
	OPTIONEE:
	
	                                
	
	  

	(Signature)
		
	Address:	 	
                     

		
		 	
                     

  
 -3- 

 Early Exercise Form 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

STOCK OPTION AGREEMENT 

1.    Grant of Option. Twist Bioscience Corporation, a Delaware corporation (the
“Company”), hereby grants to                      (“Optionee”), an option (the “Option”) to
purchase the total number of shares of Common Stock (the “Shares”) set forth in the Notice of Stock Option Grant (the “Notice”), at the exercise price per Share set forth in the Notice (the “Exercise
Price”) subject to the terms, definitions and provisions of the Twist Bioscience Corporation 2013 Stock Plan (the “Plan”) adopted by the Company, which is incorporated in this Stock Option Agreement (this
“Agreement”) by reference. Unless otherwise defined in this Agreement, the terms used in this Agreement or the Notice shall have the meanings defined in the Plan. 

2.    Designation of Option. This Option is intended to be an Incentive Stock Option as defined in
Section 422 of the Code only to the extent so designated in the Notice, and to the extent it is not so designated, or to the extent this Option does not or ceases to qualify as an Incentive Stock Option, it shall be treated as a Nonstatutory
Stock Option. 
 Notwithstanding the above, if designated as an Incentive Stock Option, in the event that the Shares subject to this Option
(and all other incentive stock options granted to Optionee by the Company or any Parent or Subsidiary, including under other plans) that first become exercisable in any calendar year have an aggregate Fair Market Value (determined for each Share as
of the date of grant of the option covering such Share) in excess of USD $100,000, this Option, to the extent the value thereof is in excess of USD $100,000, shall be treated as a Nonstatutory Stock Option, in accordance with Section 7(c) of
the Plan. 
 3.    Exercise of Option. This Option shall be exercisable during its term in
accordance with the Exercise Schedule set out in the Notice and with the provisions of Section 7(c) of the Plan as follows: 

(a)    Right to Exercise. 

(i)    This Option may not be exercised for a fraction of a share. 

(ii)    In the event of Optionee’s death, Disability or other termination of Continuous Service Status, the
exercisability of this Option is governed by Section 5 below, subject to the limitations contained in this Section 3. 

(iii)    In no event may this Option be exercised after the Expiration Date set forth in the Notice. 

(b)    Method of Exercise. 

(i)    This Option shall be exercisable by execution and delivery of the Early Exercise Notice and Restricted Stock
Purchase Agreement attached hereto as Exhibit A, the 

 
Exercise Agreement attached hereto as Exhibit B or of any other form of written notice approved for such purpose by the Company which shall state Optionee’s
election to exercise this Option, the number of Shares in respect of which this Option is being exercised, and such other representations and agreements as to the holder’s investment intent with respect to such Shares as may be required by the
Company pursuant to the provisions of the Plan. Such written notice shall be signed by Optionee and shall be delivered to the Company by such means as are determined by the Company in its discretion to constitute adequate delivery. The written
notice shall be accompanied by payment of the aggregate Exercise Price for the purchased Shares. 
 (ii)    As a
condition to the grant, vesting and exercise of this Option and as further set forth in Section 9 of the Plan, Optionee hereby agrees to make adequate provision for the satisfaction of (and will indemnify the Company and any Subsidiary or
Affiliate for) any applicable taxes or tax withholdings, social contributions, required deductions, or other payments, if any (“Tax-Related Items”), which arise upon the grant, vesting or
exercise of this Option, ownership or disposition of Shares, receipt of dividends, if any, or otherwise in connection with this Option or the Shares, whether by withholding, direct payment to the Company, or otherwise as determined by the Company in
its sole discretion. Regardless of any action the Company or any Subsidiary or Affiliate takes with respect to any or all applicable Tax-Related Items, Optionee acknowledges and agrees that the ultimate
liability for all Tax-Related Items is and remains Optionee’s responsibility and may exceed any amount actually withheld by the Company or any Subsidiary or Affiliate. Optionee further acknowledges and
agrees that Optionee is solely responsible for filing all relevant documentation that may be required in relation to this Option or any Tax-Related Items (other than filings or documentation that is the
specific obligation of the Company or any Subsidiary or Affiliate pursuant to Applicable Law), such as but not limited to personal income tax returns or reporting statements in relation to the grant, vesting or exercise of this Option, the holding
of Shares or any bank or brokerage account, the subsequent sale of Shares, and the receipt of any dividends. Optionee further acknowledges that the Company makes no representations or undertakings regarding the treatment of any Tax-Related Items and does not commit to and is under no obligation to structure the terms or any aspect of the Option to reduce or eliminate Optionee’s liability for
Tax-Related Items or achieve any particular tax result. Optionee also understands that Applicable Laws may require varying Share or option valuation methods for purposes of calculating Tax-Related Items, and the Company assumes no responsibility or liability in relation to any such valuation or for any calculation or reporting of income or Tax-Related Items
that may be required of Optionee under Applicable Laws. Further, if Optionee has become subject to Tax-Related Items in more than one jurisdiction, Optionee acknowledges that the Company or any Subsidiary or
Affiliate may be required to withhold or account for Tax-Related Items in more than one jurisdiction. 

(iii)    The Company is not obligated, and will have no liability for failure to issue or deliver any Shares upon
exercise of this Option unless such issuance or delivery would comply with the Applicable Laws, with such compliance determined by the Company in consultation with its legal counsel. Furthermore, Optionee understands that the Applicable Laws of the
country in which Optionee is residing or working at the time of grant, vesting, and/or exercise of this Option (including any rules or regulations governing securities, foreign exchange, tax, labor or other matters) may restrict or prevent exercise
of this Option. This Option may not be exercised until such time as the Plan has been approved by the holders of capital stock of the Company, or if the issuance of such Shares upon such exercise or the method of payment of

  
 -2- 

 
consideration for such Shares would constitute a violation of any Applicable Laws, including any applicable U.S. federal or state securities laws or any other law or regulation, including any
rule under Part 221 of Title 12 of the Code of Federal Regulations as promulgated by the Federal Reserve Board. As a condition to the exercise of this Option, the Company may require Optionee to make any representation and warranty to the Company as
may be required by the Applicable Laws. Assuming such compliance, for income tax purposes the Shares shall be considered transferred to Optionee on the date on which this Option is exercised with respect to such Shares, subject to Applicable Laws.

 (iv)    Subject to compliance with Applicable Laws, this Option shall be deemed to be exercised upon receipt by the
Company of the appropriate written notice of exercise accompanied by the Exercise Price and the satisfaction of any applicable obligations described in Section 3(b)(ii) above. 

4.    Method of Payment. Unless otherwise specified by the Company in its sole discretion to comply
with Applicable Laws or facilitate the administration of the Plan, payment of the Exercise Price shall be by cash or check or, following the initial public offering of the Company’s Common Stock, by Cashless Exercise pursuant to which the
Optionee delivers an irrevocable direction to a securities broker (on a form prescribed by the Company and according to a procedure established by the Company). 

Optionee understands and agrees that, if required by the Company or Applicable Laws, any cross-border cash remittance made to exercise this
Option or transfer proceeds received upon the sale of Shares must be made through a locally authorized financial institution or registered foreign exchange agency and may require Optionee to provide to such entity certain information regarding the
transaction. Moreover, Optionee understands and agrees that the future value of the underlying Shares is unknown and cannot be predicted with certainty and may decrease in value, even below the Exercise Price. Optionee understands that neither the
Company nor any Subsidiary or Affiliate is responsible for any foreign exchange fluctuation between local currency and the United States Dollar or the selection by the Company or any Subsidiary or Affiliate in its sole discretion of an applicable
foreign currency exchange rate that may affect the value of the Option (or the calculation of income or Tax-Related Items thereunder). 

5.    Termination of Relationship. Following the date of termination of Optionee’s Continuous
Service Status for any reason (the “Termination Date”), Optionee may exercise this Option only as set forth in the Notice and this Section 5. If Optionee does not exercise this Option within the Termination Period set forth in
the Notice or the termination periods set forth below, this Option shall terminate in its entirety. In no event, may any Option be exercised after the Expiration Date of this Option as set forth in the Notice. For the avoidance of doubt and for
purposes of this Option only, termination of Continuous Service Status and the Termination Date will be deemed to occur as of the date Optionee is no longer actively providing services as an Employee or Consultant (except, in certain circumstances,
to the extent Optionee is on a Company-approved leave of absence and subject to any Company policy or Applicable Laws regarding such leaves) and will not be extended by any notice period or “garden leave” that may be required contractually
or under Applicable Laws, unless otherwise determined by the Company in its sole discretion. 

  
 -3- 

 (a)    General Termination. In the event of termination
of Optionee’s Continuous Service Status other than as a result of Optionee’s Disability or death or Optionee’s termination by the Company for Cause, Optionee may, to the extent Optionee is vested in the Optioned Stock, exercise this
Option during the Termination Period set forth in the Notice (but in no event later than the Expiration Date). 

(b)    Termination upon Disability of Optionee. In the event of termination of Optionee’s
Continuous Service Status as a result of Optionee’s Disability, Optionee may, but only within 12 month(s) following the Termination Date, exercise this Option to the extent Optionee is vested in the Optioned Stock. 

(c)    Death of Optionee. In the event of termination of Optionee’s Continuous Service Status as
a result of Optionee’s death, or in the event of Optionee’s death within 3 month(s) following Optionee’s Termination Date, this Option may be exercised at any time within 12 month(s) following the Termination Date, or if later, 12
month(s) following the date of death (but in each case, in no event later than the Expiration Date) by any beneficiaries designated in accordance with Section 16 of the Plan or, if there are no such beneficiaries, by the Optionee’s estate,
or by a person who acquired the right to exercise the Option by bequest or inheritance, but only to the extent Optionee is vested in this Option. 

(d)    Termination for Cause. In the event of termination of Optionee’s Continuous Service
Status by the Company for Cause, this Option (including any vested portion thereof) shall immediately terminate in its entirety upon first notification to Optionee of such termination by the Company for Cause. If Optionee’s Continuous Service
Status is suspended pending an investigation of whether Optionee’s Continuous Service Status will be terminated by the Company for Cause, all Optionee’s rights under this Option, including the right to exercise this Option, shall be
suspended during the investigation period. 
 6.    Non-Transferability of
Option. This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised during the lifetime of Optionee only by him or her, subject to the terms of the Plan and
the Stockholders Agreement. The terms of this Option shall be binding upon the executors, administrators, heirs, successors and assigns of Optionee. 

7.    Lock-Up Agreement. Without limitation on anything in
the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters in connection with the initial public offering of the Company’s securities registered under the
Securities Act of 1933, as amended, Optionee shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of or
otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the effective date of the relevant registration statement filed under the Securities Act in connection with
the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant registration statement in connection with any other public offering of registrable securities, as such
underwriter shall specify reasonably and in good faith. 

  
 -4- 

 8.    Effect of Agreement. Optionee acknowledges receipt of a
copy of the Plan and represents that he or she is familiar with the terms and provisions thereof (and has had an opportunity to consult counsel regarding the Option terms), and hereby accepts this Option and agrees to be bound by its contractual
terms as set forth herein and in the Plan. Optionee hereby agrees to accept as binding, conclusive and final all decisions and interpretations of the Administrator regarding any questions relating to this Option. In the event of a conflict between
the terms and provisions of the Plan and the terms and provisions of the Notice and this Agreement, the Plan terms and provisions shall prevail. 

9.    Imposition of Other Requirements. The Company reserves the right, without Optionee’s
consent, to cancel or forfeit outstanding grants or impose other requirements on Optionee’s participation in the Plan, on this Option and the Shares subject to this Option and on any other Award or Shares acquired under the Plan, to the extent
the Company determines it is necessary or advisable in order to comply with Applicable Laws or facilitate the administration of the Plan. Optionee agrees to sign any additional agreements or undertakings that may be necessary to accomplish the
foregoing. Furthermore, Optionee acknowledges that the Applicable Laws of the country in which Optionee is residing or working at the time of grant, holding, vesting, and exercise of the Option or the holding or sale of Shares received pursuant to
the Option (including any rules or regulations governing securities, foreign exchange, tax, labor, or other matters) may subject Optionee to additional procedural or regulatory requirements that Optionee is and will be solely responsible for and
must fulfill. If applicable, such requirements may be outlined in but are not limited to the Country-Specific Addendum (the “Addendum”) attached hereto, which forms part of this Agreement. Notwithstanding any provision herein,
Optionee’s participation in the Plan shall be subject to any applicable special terms and conditions or disclosures as set forth in the Addendum. The Optionee also understands and agrees that if the Optionee works, resides, moves to, or
otherwise is or becomes subject to Applicable Laws or Company policies of another jurisdiction at any time, certain country-specific notices, disclaimers and/or terms and conditions may apply to him as from the date of grant, unless otherwise
determined by the Company in its sole discretion. 
 10.    Electronic Delivery and Translation.
The Company may, in its sole discretion, decide to deliver any documents related to Optionee’s current or future participation in the Plan, this Option, the Shares subject to this Option, any other Company Securities or any other
Company-related documents, by electronic means. By accepting this Option, whether electronically or otherwise, Optionee hereby (i) consents to receive such documents by electronic means, (ii) consents to the use of electronic signatures,
and (iii) if applicable, agrees to participate in the Plan and/or receive any such documents through an on-line or electronic system established and maintained by the Company or a third party designated
by the Company, including but not limited to the use of electronic signatures or click-through electronic acceptance of terms and conditions. To the extent Optionee has been provided with a copy of this Agreement, the Plan, or any other documents
relating to this Option in a language other than English, the English language documents will prevail in case of any ambiguities or divergences as a result of translation. 

11.    No Acquired Rights or Employment Rights. In accepting the Option, Optionee acknowledges that the Plan
is established voluntarily by the Company, is discretionary in nature, and may be modified, amended, suspended or terminated by the Company at any time. The grant of the Option is voluntary and occasional and does not create any contractual or other
right to 

  
 -5- 

 
receive future grants of Options, other Awards or benefits in lieu of Options, even if Options have been granted repeatedly in the past, and all decisions with respect to future grants of Options
or other Awards, if any, will be at the sole discretion of the Company. In addition, Optionee’s participation in the Plan is voluntary, and the Option and the Shares subject to the Option are extraordinary items that do not constitute regular
compensation for services rendered to the Company or any Subsidiary or Affiliate and are outside the scope of Optionee’s employment contract, if any. The Option and the Shares subject to the Option are not intended to replace any pension rights
or compensation and are not part of normal or expected salary or compensation for any purpose, including but not limited to calculating severance payments, if any, upon termination. 

Nothing contained in this Agreement is intended to constitute or create a contract of employment, nor shall it constitute or create the right
to remain associated with or in the employ of the Company or any Subsidiary or Affiliate for any particular period of time. This Agreement shall not interfere in any way with the right of the Company or any Subsidiary or Affiliate to terminate
Optionee’s employment or service at any time, subject to Applicable Laws. 
 12.    Data Privacy.
Optionee hereby explicitly and unambiguously consents to the collection, use and transfer, whether in electronic or other form, of Optionee’s personal data (as described below) by and among, as applicable, the Company and any Subsidiary
or Affiliate or third parties as may be selected by the Company, for the exclusive purpose of implementing, administering, and managing Optionee’s participation in the Plan. Optionee understands that refusal or withdrawal of consent may affect
Optionee’s ability to participate in the Plan or to realize benefits from the Option. 
 Optionee understands that the
Company and any Subsidiary or Affiliate may hold certain personal information about Optionee, including, but not limited to, Optionee’s name, home address and telephone number, date of birth, social insurance number or other identification
number, salary, nationality, job title, any shares of stock or directorships held in the Company or any Subsidiary or Affiliate, details of all Options or any other entitlement to Shares awarded, canceled, exercised, vested, unvested or outstanding
in Optionee’s favor (“Personal Data”). Optionee understands that Personal Data may be transferred to any Subsidiary or Affiliate or third parties assisting in the implementation, administration and management of the Plan, that
these recipients may be located in the United States, Optionee’s country, or elsewhere, and that the recipient’s country may have different data privacy laws and protections than Optionee’s country. 

13.    Optionee Representations (Regulation S). Optionee represents and warrants that he or she is
not a U.S. Person (as defined in Rule 902(k) of Regulation S of the Securities Act of 1933, as amended (the “Securities Act”), as it may be amended from time to time (“Regulation S”)) and was not in the United
States as of the Date of Grant and is not currently in the United States. Optionee further acknowledges that the Company has not engaged in any directed selling efforts (as such term is defined in Regulation S) in connection with the option to
purchase Shares granted by this Agreement. Optionee acknowledges that the grant of this Option and the offer and sale of Shares acquired upon exercise of this Option is being made in compliance with Regulation S which, among other things, restricts
the transfer of the Shares underlying the Option as set forth in the Exercise Agreement. 

  
 -6- 

 14.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted
only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Plan and the Notice, set forth the entire
agreement and understanding of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the subject matter hereof. 

(c)    Amendments and Waivers. No modification of or amendment to this Agreement, nor any waiver of
any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of that provision as to that or
any other instance. 
 (d)    Successors and Assigns. Except as otherwise provided in this
Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal representatives. The Company may
assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior written consent of
the Company. 
 (e)    Notices. Any notice, demand or request required or permitted to be given
under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or registered mail with postage prepaid,
addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most recent address set forth in the
Company’s books and records. 
 (f)    Severability. If one or more provisions of this
Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then
(i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its
terms. 
 (g)    Construction. This Agreement is the result of negotiations between and has been
reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the
parties hereto. 

  
 -7- 

 (h)    Counterparts. This Agreement may be executed in
any number of counterparts, each of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Code Section 409A. It is intended that the Option comply with or be
exempt from Section 409A of the Code, and this Agreement shall be limited, construed and interpreted in accordance with such intent; provided, that for the avoidance of doubt, this provision shall not be construed to require a gross-up payment in respect of any taxes, interest or penalties imposed on the Optionee as a result of Section 409A of the Code, and by accepting this Option grant, the Optionee agrees and acknowledges that the
Company be held liable for any applicable costs, taxes, or penalties associated with this Option or this Agreement under Code Section 409A or otherwise. 

  
 -8- 

 Country-Specific Addendum 

This Addendum includes additional country-specific notices, disclaimers, and/or terms and conditions that apply to individuals who are working or residing in
the countries listed below and that may be material to Optionee’s participation in the Plan. Such notices, disclaimers, and/or terms and conditions may also apply, as from the date of grant, if the Optionee moves to or otherwise is or becomes
subject to the Applicable Laws or company policies of the country listed. However, because foreign exchange regulations and other local laws are subject to frequent change, Optionee is advised to seek advice from his or her own personal legal and
tax advisor prior to accepting or exercising an Option or holding or selling Shares acquired under the Plan. The Company is not providing any tax, legal or financial advice, nor is the Company making any recommendations regarding Optionee’s
acceptance of the Option or participation in the Plan. Unless otherwise noted below, capitalized terms shall have the same meaning assigned to them under the Plan, the Notice of Stock Option Grant and the Stock Option Agreement. This Addendum forms
part of the Stock Option Agreement and should be read in conjunction with the Stock Option Agreement and the Plan. 
 Securities Law Notice: Unless
otherwise noted, neither the Company nor the Shares are registered with any local stock exchange or under the control of any local securities regulator outside the United States. The Stock Option Agreement (of which this Addendum is a part), the
Notice of Stock Option Grant, the Plan, and any other communications or materials that you may receive regarding participation in the Plan do not constitute advertising or an offering of securities outside the United States, and the issuance of
securities described in any Plan-related documents is not intended for public offering or circulation in your jurisdiction. 
  

 
  

			
	European Union	  	 The following supplements Section 12 of the Stock Option Agreement:

 
 Data Privacy. Optionee understands that Personal Data will be held
only as long as is necessary to implement, administer and manage the Optionee’s participation in the Plan. The Optionee understands that he or she may, at any time, view his or her Personal Data, request
additional information about the storage and processing of Personal Data, require any necessary amendments to Personal Data without cost or refuse or withdraw the consents herein by contacting in writing the Company’s representative relating to
Plan or Option matters, who may be contacted at [insert]. 

		
	Belgium	  	Belgium Option Acceptance. For Belgian tax purposes you are not permitted to accept this Option grant until after the 60th day following the Offer Date, which is defined
under Belgian tax law as the date that the grant (including this Agreement and other relevant documentation) is communicated to you. Any acceptance of this option shall be automatically deemed to be accepted after the 60th day following such Offer Date. You should consult with your personal tax advisor regarding the Option and your liability for income taxes and social
contributions.

  
 -9- 

  

			
		
	Denmark	  	 Foreign Account Reporting. Danish resident holders of non-Danish bank accounts or accounts
with non-Danish brokers should submit certain forms to the Danish tax authorities:
  

Erklæring V regarding shares deposited with a non-Danish bank or broker
(https://www.skat.dk/SKAT.aspx?oId=90030)
 Erklæring K regarding money deposited with a
non-Danish bank or broker (https://www.skat.dk/SKAT.aspx?oId=73344
  

	 	 
	Singapore	  	 Securities Law Notice. This offer and the Shares to be issued hereunder shall be made available through this platform/facility and
are offered to you in reliance on the exemption under section 272A (1) of the Securities and Futures Act (Chapter 289) of Singapore (the “SFA”). These offers are not made in or accompanied by a prospectus that is registered by the
Monetary Authority of Singapore (the “Authority”). Apart from being subjected to the general resale restriction under Section 257 of the SFA, any and all Shares to be issued hereunder shall therefore not be subsequently sold to any
person, unless the offer resulting in such subsequent sale is made in compliance with Subdivisions (2) and (3) of Part XII Division (1), in reliance on subsection (8)(c) or any other exemption under any provision of Subdivision
(4) of Part XII Division (1) (other than this subsection), or where at least 6 months have elapsed from the date the securities were acquired under the initial offer, in reliance on the exemption under this subsection.

 
 Director Reporting. If you are a director or shadow director of the Company or an
affiliate, you may be subject to special reporting requirements with regard to the acquisition of shares or rights over shares. Please contact your personal legal advisor for further details if you are a director or shadow director.

 
 Exit Tax / Deemed Exercise Rule. If you are deemed by the Singapore tax
authorities to have received Options in relation to your employment in Singapore, notwithstanding the fact that you are not employed by the Company or any Subsidiary or Affiliate, please note that if, prior to the exercise of the Options, you are 1)
a permanent resident of Singapore and leave Singapore permanently or are transferred out of Singapore; or 2) neither a Singapore citizen nor permanent resident and either cease employment in Singapore or leave Singapore for any period exceeding 3
months, you will likely be taxed on the Options on a “deemed exercise” basis, even if your Options have not yet vested. You should discuss your tax treatment with your personal tax
advisor.

  
 -10- 

			
	 	 
	United Kingdom	  	 The following supplements Section 3(b)(ii) of the Agreement:

 
 Withholding of Tax. If payment or withholding (if applicable)
of the Tax-Related Items is not made within ninety (90) days of the end of the UK tax year in which the event giving rise to the Tax-Related Items occurs (the
“Due Date”) or such other period specified in Section 222(1)(c) of the Income Tax (Earnings and Pensions) Act 2003, the amount of any uncollected Tax-Related Items will constitute a loan
owed by Optionee to the Employer (if applicable), effective on the Due Date. Optionee agrees that the loan will bear interest at the then-current Official Rate of Her Majesty’s Revenue and Customs (“HMRC”), it will be
immediately due and repayable, and the Company or the employer may recover it at any time thereafter by any of the means referred to in Section 3(b)(ii) of the Agreement. Notwithstanding the foregoing, if Optionee is a director or
executive officer of the Company (within the meaning of Section 13(k) of the U.S. Securities and Exchange Act of 1934, as amended), Optionee will not be eligible for such a loan to cover the Tax-Related
Items. In the event that Optionee is a director or executive officer and the Tax-Related Items are not collected from or paid by Optionee by the Due Date, the amount of any uncollected Tax-Related Items will constitute a benefit to Optionee on which additional income tax and national insurance contributions will be payable. Optionee will be responsible for reporting and paying any income tax
due on this additional benefit directly to HMRC under the self-assessment regime.
  

HMRC National Insurance Contributions. Optionee agrees that:
  

(a)   Tax-Related Items within Section 3(b)(ii) of the
Agreement shall include any secondary class 1 (employer) National Insurance Contributions that:
  

(i) any employer (or former employer) of the Optionee is liable to pay (or reasonably believes it is liable to
pay); and
  
 (ii)  may be lawfully
recovered from the Optionee; and
  

(b)   if required to do so by the Company (at any time when the relevant election can be made) the
Optionee shall either:
  
 (i) make a joint
election (with the employer or former employer) in the form provided by the Company to transfer to the Optionee the whole or any part of the employer’s liability that falls within Section 3(b)(ii) of the Agreement; and

 
 (ii)  enter into arrangements
required by HM Revenue & Customs (or any other tax authority) to secure the payment of the transferred liability; or
  

(iii)  hereby indemnifies the Company and any Subsidiary or Affiliate against all and any Tax-Related Items which may arise in respect of or in connection with (a) this Option, (b) any option granted or

  
 -11- 

			
		  	 provided to Optionee by way of rollover, assumption or replacement of this Option, or (c) the Shares or other
securities issued or transferred pursuant to the exercise of this Option or any option granted or provided to Optionee by way of rollover, assumption or replacement of this Option.

		
		  	 Restricted Securities Elections. Unless this requirement is waived by the Company, the Optionee shall
enter into a joint election (with the appropriate employer) under section 431(1) or section 431(2) of Income Tax (Earnings & Pensions) Act 2003 in respect of:
  

(a)   any Shares acquired (or to be acquired) on exercise of the Option;

 
 (b)   any securities acquired
(or to be acquired) as a result of any surrender of the Option; and
  

(c)   any securities acquired (or to be acquired) as a result of holding either Shares acquired on
exercise of the Option or securities specified in paragraph (b) above or this paragraph (c).

  
 -12- 

 EXHIBIT A 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EARLY EXERCISE NOTICE AND RESTRICTED STOCK PURCHASE AGREEMENT 

This Agreement (“Agreement”) is made as of
                     by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan (the “Plan”) and the Option Agreement (as defined below). 

2.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). Of these Shares,
Purchaser has elected to purchase                  of those Shares which have become vested as of the date hereof under the Vesting Schedule set forth in the Notice of
Stock Option Grant (the “Vested Shares”) and                  Shares which have not yet vested under such Vesting Schedule (the “Unvested
Shares”). The purchase price for the Shares shall be USD $         per Share for a total purchase price of USD $        . The term “Shares”
refers to the purchased Shares and all securities received in connection with the Shares pursuant to stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like,
and all new, substituted or additional securities or other property to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares. 

3.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 4.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Purchaser shall not assign, encumber or dispose of any interest in the Shares while the Shares are subject to the Company’s
Repurchase Option (as defined below). After any Shares have been released from such Repurchase Option, Purchaser shall not assign, encumber or dispose of any interest in such Shares except in compliance with the Stockholders Agreement. 

  
 -13- 

 (a)    Repurchase Option. 

(i)    In the event of the voluntary or involuntary termination of Purchaser’s Continuous Service Status with the
Company for any reason (including, without limitation, resignation, death or Disability), with or without Cause, the Company shall upon the date of such termination (the “Termination Date”) have an irrevocable, exclusive option (the
“Repurchase Option”) for a period of 3 months from such date to repurchase all or any portion of the Unvested Shares (as defined below) held by Purchaser as of the Termination Date at the original purchase price per Share (adjusted
for any stock splits, stock dividends and the like) specified in Section 1. As used herein, “Unvested Shares” means Shares that have not yet been released from the Repurchase Option. 

(ii)    Unless the Company notifies Purchaser within 3 months from the Termination Date that it does not intend to
exercise its Repurchase Option with respect to some or all of the Unvested Shares, the Repurchase Option shall be deemed automatically exercised by the Company as of the end of such 3-month period following
such termination, provided that the Company may notify Purchaser that it is exercising its Repurchase Option as of a date prior to the end of such 3-month period. Unless Purchaser is otherwise notified by the
Company pursuant to the preceding sentence that the Company does not intend to exercise its Repurchase Option as to some or all of the Unvested Shares to which it applies at the time of termination, execution of this Agreement by Purchaser
constitutes written notice to Purchaser of the Company’s intention to exercise its Repurchase Option with respect to all Unvested Shares to which such Repurchase Option applies. The Company, at its choice, may satisfy its payment obligation to
Purchaser with respect to exercise of the Repurchase Option by either (A) delivering a check to Purchaser in the amount of the purchase price for the Unvested Shares being repurchased, or (B) in the event Purchaser is indebted to the
Company, canceling an amount of such indebtedness equal to the purchase price for the Unvested Shares being repurchased, or (C) by a combination of (A) and (B) so that the combined payment and cancellation of indebtedness equals such
purchase price. In the event of any deemed automatic exercise of the Repurchase Option pursuant to this Section 3(a)(ii) in which Purchaser is indebted to the Company, such indebtedness equal to the purchase price of the Unvested Shares being
repurchased shall be deemed automatically canceled as of the end of such 3-month period following termination of Purchaser’s employment or consulting relationship unless the Company otherwise satisfies
its payment obligations. As a result of any repurchase of Unvested Shares pursuant to this Section 3(a), the Company shall become the legal and beneficial owner of the Unvested Shares being repurchased and shall have all rights and interest
therein or related thereto, and the Company shall have the right to transfer to its own name the number of Unvested Shares being repurchased by the Company, without further action by Purchaser. 

(iii)    One hundred percent (100%) of the Shares shall initially be subject to the Repurchase Option. The Unvested
Shares shall be released from the Repurchase Option in accordance with the Vesting Schedule set forth in the Notice of Stock Option Grant until all Shares are released from the Repurchase Option; provided, however, that such scheduled releases from
the Repurchase Option shall immediately cease as of the Termination Date. Fractional shares shall be rounded to the nearest whole share. 

(b)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein will
receive and hold such Shares or interest subject to the provisions of this 

  
 -14- 

 
Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of the Option Agreement, including, without limitation, Section 7 of
the Option Agreement and, insofar as applicable, the Repurchase Option. In the event the Repurchase Option is deemed exercised by the Company pursuant to Section 3(a)(ii) hereof, the Company may deem any transferee to have transferred the
Shares or interest to Purchaser prior to their purchase by the Company, and payment of the purchase price by the Company to such transferee shall be deemed to satisfy Purchaser’s obligation to pay such transferee for such Shares or interest,
and also to satisfy the Company’s obligation to pay Purchaser for such Shares or interest. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

(c)    Lock-Up Agreement. The
lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 
 5.    Escrow of Unvested Shares. For purposes of facilitating the enforcement of the
provisions of Section 3(a) above, Purchaser agrees, immediately upon receipt of the stock certificate or, in the case of uncertificated securities, notice of issuance, for the Shares subject to the Repurchase Option, to deliver any such stock
certificate(s), as well as a Stock Power in the form attached to this Agreement as Attachment A executed by Purchaser and by Purchaser’s spouse (if required for transfer), in blank, to the Secretary of the Company, or
the Secretary’s designee, to hold such Shares (and such stock certificate(s), if any) and Stock Power in escrow and to take all such actions and to effectuate all such transfers and/or releases as are required in accordance with the terms of
this Agreement. Purchaser hereby acknowledges that the Secretary of the Company, or the Secretary’s designee, is so appointed as the escrow holder with the foregoing authorities as a material inducement to make this Agreement and that said
appointment is coupled with an interest and is accordingly irrevocable. Purchaser agrees that said escrow holder shall not be liable to any party hereof (or to any other party). The escrow holder may rely upon any letter, notice or other document
executed by any signature purported to be genuine and may resign at any time. Purchaser agrees that if the Secretary of the Company, or the Secretary’s designee, resigns as escrow holder for any or no reason, the Board shall have the power to
appoint a successor to serve as escrow holder pursuant to the terms of this Agreement. 
 6.    Investment and
Taxation Representations. In connection with the purchase of the Shares, Purchaser represents to the Company the following: 

(a)    Purchaser is aware of the Company’s business affairs and financial condition and has acquired sufficient
information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment for Purchaser’s own account only and not with a view to, or for resale in connection with,
any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any present intention to transfer the Shares to any other person or entity. 

(b)    Purchaser understands that the Shares have not been registered under the Securities Act by reason of a specific
exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

  
 -15- 

 (c)    Purchaser further acknowledges and understands that the securities
must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption from such registration is available and unless any such disposition is in compliance with Regulation S. Purchaser further acknowledges and
understands that the Company is under no obligation to register the securities. 
 (d)    Purchaser is familiar with the
provisions of Rule 144 and Regulation S (Rules 901 through 905 and the Preliminary Notes thereto), each promulgated under the Securities Act, which, in substance, permits limited public resale of “restricted securities” acquired,
directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to the satisfaction of certain conditions. Purchaser understands that the
Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the Company be subject to the reporting requirements of the Exchange Act, that
resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of securities be limited in volume and take place only pursuant to brokered
transactions. Purchaser further understands that the Company provides no assurances as to whether Purchaser will be able to sell any or all of the Shares pursuant to Regulation S. Notwithstanding this Section 5(d), Purchaser acknowledges and
agrees to the restrictions set forth in Section 5(e) below. 
 (e)    Purchaser further understands that in the
event all of the applicable requirements of Rule 144 or Regulation S are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding
the fact that Rule 144 and Regulation S are not exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and
otherwise than pursuant to Rule 144 or Regulation S will have a substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who
participate in such transactions do so at their own risk. 
 (f)    Purchaser understands that Purchaser may suffer
adverse tax consequences as a result of Purchaser’s purchase or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the
Shares and that Purchaser is not relying on the Company for any tax advice. 
 (g)    Purchaser hereby acknowledges that
Purchaser has received, read, and understands this Agreement and attachments thereto and agrees to be bound by its terms and conditions, including (without limitation), Section 9 below. Purchaser has signed and understands and confirms the
representations made in the Investor Certificate attached to this Agreement as Exhibit C. 
 7.    Voting
Provisions. As condition precedent to entering into this Agreement, Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing
to be bound by and subject to the terms of the Stockholders Agreement, including the restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement.

  
 -16- 

 8.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws, including, but not limited to, the
following legends: 
 (iv)    “THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON
TRANSFER, INCLUDING ANY APPLICABLE RESALE RESTRICTIONS AND OTHER REQUIREMENTS OF REGULATION S OF THE SECURITIES ACT OF 1933. SUCH TRANSFER RESTRICTIONS ARE BINDING ON TRANSFEREES OF THESE SECURITIES.” 

(v)    “THE SHARES MAY NOT BE MADE SUBJECT TO HEDGING TRANSACTIONS UNLESS SUCH TRANSACTIONS ARE CONDUCTED IN
COMPLIANCE WITH THE SECURITIES ACT OF 1933, INCLUDING REGULATION S THEREUNDER.” 
 (b)    Stop-Transfer
Notices. Purchaser agrees that, in order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company
transfers its own securities, it may make appropriate notations to the same effect in its own records. 

(c)    Refusal to Transfer. The Company shall not be required (i) to transfer on its books any
Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or other transferee to whom
such Shares shall have been so transferred. 
 9.    No Employment Rights. Nothing in this
Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or without cause. 

10.    Section 83(b) Election. 

(a)    Purchaser understands that Section 83(a) of the Internal Revenue Code of 1986, as amended (the
“Code”), taxes as ordinary income for a Nonstatutory Stock Option and as alternative minimum taxable income for an Incentive Stock Option the difference between the amount paid for the Shares and the Fair Market Value of the Shares
as of the date any restrictions on the Shares lapse. In this context, “restriction” means the right of the Company to buy back the Shares pursuant to the Repurchase Option set forth in Section 3(a) of this Agreement. Purchaser
understands that Purchaser may elect to be taxed at the time the Shares are purchased, rather than when and as the Repurchase Option expires, by filing an election under Section 83(b) (an “83(b) Election”) of the Code with the
Internal Revenue Service within 30 days from the date of purchase. Even if the Fair Market Value of the Shares at the time of the execution of this Agreement equals the amount paid for the Shares, the election must be made to avoid income and
alternative minimum tax treatment under Section 83(a) in the future. Purchaser understands that failure to file such an election in a timely manner may result in adverse tax consequences for Purchaser.

  
 -17- 

 
Purchaser further understands that an additional copy of such election form should be filed with his or her federal income tax return for the calendar year in which the date of this Agreement
falls. Purchaser acknowledges that the foregoing is only a summary of the effect of United States federal income taxation with respect to purchase of the Shares hereunder, and does not purport to be complete, and is not intended or written to be
used, and cannot be used, for the purposes of avoiding taxpayer penalties. Purchaser further acknowledges that the Company has directed Purchaser to seek independent advice regarding the applicable provisions of the Code, the income tax laws of any
municipality, state or foreign country in which Purchaser may reside, and the tax consequences of Purchaser’s death, and Purchaser has consulted, and has been fully advised by, Purchaser’s own tax advisor regarding such tax laws and tax
consequences or has knowingly chosen not to consult such a tax advisor. Purchaser further acknowledges that neither the Company nor any subsidiary or representative of the Company has made any warranty or representation to Purchaser with respect to
the tax consequences of Purchaser’s purchase of the Shares or of the making or failure to make an 83(b) Election. PURCHASER (AND NOT THE COMPANY, ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR APPROPRIATELY FILING SUCH FORM
WITH THE IRS, EVEN IF PURCHASER REQUESTS THE COMPANY, ITS AGENTS OR ANY OTHER PERSON MAKE THIS FILING ON PURCHASER’S BEHALF. 

(b)    Purchaser agrees that he or she will execute and deliver to the Company with this executed Agreement a copy of the
Acknowledgment and Statement of Decision Regarding Section 83(b) Election (the “Acknowledgment”) attached hereto as Attachment B. Purchaser further agrees that he or she will execute and submit with
the Acknowledgment a copy of the 83(b) Election attached hereto as Attachment C (for tax purposes in connection with the early exercise of an option) if Purchaser has indicated in the Acknowledgment his or her decision to
make such an election. 
 11.    Waiver of Statutory Information Rights. Purchaser acknowledges and
understands that, but for the waiver made herein, Purchaser would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s stock ledger, a
list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the General Corporation Law of Delaware (any and
all such rights, and any and all such other rights of Purchaser as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the general
public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Purchaser hereby unconditionally and irrevocably waives the Inspection Rights,
whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign,
transfer, or cause to be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Purchaser in Purchaser’s capacity as a stockholder
and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Purchaser under any written agreement with the Company. 

  
 -18- 

 12.    Restriction on Transfer of Shares. Notwithstanding any
provisions to the contrary, Purchaser shall not offer or sell any Shares received pursuant to this Agreement in an unregistered transaction to a U.S. Person or for the account or benefit of a U.S. Person prior to the expiration of the one year
anniversary (or the six-month anniversary if the Company is a “reporting issuer,” as defined in Rule 902 under the Securities Act) of the date on which the Shares are issued by the Company under this
Agreement. Any Shares offered or sold prior to the expiration of the one year anniversary (or the six-month anniversary if the Company is a “reporting issuer,” as defined in Rule 902 under the
Securities Act) of the issuance of the Shares may be offered or sold only pursuant to the following conditions: 

(b)    the purchaser of the Shares certifies that it is not a U.S. Person and is not acquiring the Shares for the account
or benefit of any U.S. Person or is a U.S. Person who purchased the Shares in a transaction that did not require registration under the Securities Act; 

(c)    the purchaser of the Shares agrees to resell such Shares only in accordance with the provisions of Regulation S,
pursuant to registration under the Securities Act, or pursuant to another available exemption or safe harbor from registration under the Securities Act, and agrees not to engage in hedging transactions with regard to the transferred Shares unless in
compliance with the Securities Act; and 
 (d)    the certificate evidencing the Shares shall contain restrictive
legends to a similar effect as described in Subsection (b) of this Section 11. 
 Purchaser further acknowledges that other local
laws applicable to the Shares may prohibit the offer and sale of any Shares received pursuant to this Agreement to other persons and that prior to making any such offer or sale, Purchaser should consult with his or her own personal legal advisor.

 13.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or amendment to this
Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of
that provision as to that or any other instance. 

  
 -19- 

 (d)    Successors and Assigns. Except as otherwise
provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal representatives.
The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior
written consent of the Company. 
 (e)    Notices. Any notice, demand or request required or
permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or registered mail
with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most recent address
set forth in the Company’s books and records. 
 (f)    Severability. If one or more
provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 
 (g)    Construction. This Agreement is the result of negotiations
between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against
any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed in any number
of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the
statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or
otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

  
 -20- 

 Early Exercise Form 

The parties have executed this Early Exercise Notice and Restricted Stock Purchase Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION

 
			
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

 
			
	
	PURCHASER:

 
			
	
	                                   
     
	
	  

			
	(Signature)	 	
		
	Address:	 	  

		
		 	  

		
	Email:	 	  

 I,
                    , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

  
 -2- 

 ATTACHMENT A 

STOCK POWER 
 FOR
VALUE RECEIVED, the undersigned (“Holder”), hereby sells, assigns and transfers unto
                                         
                    (“Transferee”)                  shares
of the Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), standing in Holder’s name on the Company’s books as Certificate No.
CS-         whether held in certificated or uncertificated form, and does hereby irrevocably constitute and appoint
                                         to
transfer said stock on the books of the Company with full power of substitution in the premises. 
  

							
	Dated:                                     
                        	 		 		 	HOLDER:
				
		 		 		 	                    
				
		 		 		 	
                     

		 		 		 	(Signature)
				
		 		 		 	
                     

		 		 		 	Spouse of Holder (if applicable)

 This Stock Power may only be used as authorized by the Early Exercise Notice and Restricted Stock Purchase
Agreement between the Holder and the Company, dated                      and the exhibits thereto. 

Instructions: Please do not fill in any blanks other than the signature line. The purpose of this assignment is to enable the
Company to exercise its repurchase option set forth in the Agreement without requiring additional signatures on the part of Holder. 

  
 -3- 

 Early Exercise Form 

IF YOU WISH TO MAKE A SECTION 83(B) ELECTION, THE FILING OF SUCH ELECTION IS YOUR RESPONSIBILITY. 

THE FORM FOR MAKING THIS SECTION 83(B) ELECTION IS ATTACHED TO THIS AGREEMENT. 

YOU MUST FILE THIS FORM WITHIN 30 DAYS OF PURCHASING THE SHARES. 

YOU (AND NOT THE COMPANY, ANY OF ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR FILING SUCH FORM WITH THE IRS, EVEN IF YOU
REQUEST THE COMPANY, ITS AGENTS OR ANY OTHER PERSON TO MAKE THIS FILING ON YOUR BEHALF AND EVEN IF THE COMPANY, ANY OF ITS AGENTS OR ANY OTHER PERSON HAS PREVIOUSLY MADE THIS FILING ON YOUR BEHALF. 

The election should be filed by mailing a signed election form by certified mail, return receipt requested to the IRS Service Center where you file your tax
returns. See www.irs.gov. 

 Early Exercise Form 

ATTACHMENT B 

ACKNOWLEDGMENT AND STATEMENT OF DECISION 

REGARDING SECTION 83(b) ELECTION 

The undersigned has entered into a stock purchase agreement with Twist Bioscience Corporation, a Delaware corporation (the
“Company”), pursuant to which the undersigned is purchasing                  shares of Common Stock of the Company (the “Shares”). In
connection with the purchase of the Shares, the undersigned hereby represents as follows: 
 1.    The undersigned has
carefully reviewed the stock purchase agreement pursuant to which the undersigned is purchasing the Shares. 
 2.    The
undersigned either [check and complete as applicable]: 
 (i)        has consulted, and has been
fully advised by, the undersigned’s own tax advisor,
                                        , whose
business address is
                                        ,
regarding the federal, state and local tax consequences of purchasing the Shares, and particularly regarding the advisability of making elections pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended (the
“Code”) and pursuant to the corresponding provisions, if any, of applicable state law; or 

(ii)        has knowingly chosen not to consult such a tax advisor. 

3.    The undersigned hereby states that the undersigned has decided [check as applicable]: 

 

					
	(a)	 	        	  	to make an election pursuant to Section 83(b) of the Code, and is submitting to the Company, together with the undersigned’s executed stock purchase agreement, an executed form entitled “Election Under
Section 83(b) of the Internal Revenue Code of 1986;” or
			
	(b)	 	        	  	not to make an election pursuant to Section 83(b) of the Code.

 4.    Neither the Company nor any subsidiary or representative of the Company has made any
warranty or representation to the undersigned with respect to the tax consequences of the undersigned’s purchase of the Shares or of the making or failure to make an election pursuant to Section 83(b) of the Code or the corresponding
provisions, if any, of applicable state law. 
  

							
	Dated:                                     
                        	 		 		 	PURCHASER:
				
		 		 		 	                    
				
		 		 		 	
                     

		 		 		 	(Signature)
				
		 		 		 	
                     

		 		 		 	Spouse of Purchaser (if applicable)

 ATTACHMENT C 

ELECTION UNDER SECTION 83(B) 

OF THE INTERNAL REVENUE CODE OF 1986 

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code, to include in taxpayer’s gross
income or alternative minimum taxable income, as applicable, for the current taxable year, the amount of any income that may be taxable to taxpayer in connection with taxpayer’s receipt of the property described below: 

 

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

NAME OF TAXPAYER:
                     
 NAME OF
SPOUSE:                      

ADDRESS:
                                 

IDENTIFICATION NO. OF TAXPAYER:
                     

IDENTIFICATION NO. OF SPOUSE:
                     
 TAXABLE
YEAR:                      

2.    The property with respect to which the election is made is described as follows: 

                 shares of the Common Stock of Twist
Bioscience Corporation, a Delaware corporation (the “Company”). 
 3.    The date on which the property was transferred
is:                      

4.    The property is subject to the following restrictions: 

Repurchase option at cost in favor of the Company upon termination of taxpayer’s employment or consulting relationship. 

 

	5.	The fair market value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms will never lapse, of such property is: USD
$        . 

 6.    The amount (if any) paid for such property: USD
$        . 

 The undersigned has submitted a copy of this statement to the person for whom the services were performed in
connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the services in connection with the transfer of said property. 

The undersigned understands that the foregoing election may not be revoked except with the consent of the Commissioner. 

 

					
	Dated:
                                         
                   	 		 	PURCHASER:
			
		 		 	                     

 
  

		 		 	(Signature)
			
		 		 	  

		 		 	Spouse of Purchaser (if applicable)

  
 -2- 

 EXHIBIT B 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EXERCISE AGREEMENT 

This Exercise Agreement (this “Agreement”) is made as of
                    , by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). The purchase
price for the Shares shall be USD $                 per Share, for a total purchase price of USD $        . 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Purchaser shall not assign, encumber or dispose of any interest in the Shares except in compliance with the Stockholders Agreement.

 (a)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein
will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of the Option Agreement, including, without
limitation, Section 7 of the Option Agreement. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

(b)    Lock-Up Agreement. The
lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 

 4.    Investment and Taxation Representations. In
connection with the purchase of the Shares, Purchaser represents to the Company the following: 
 (k)    Purchaser is
aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment
for Purchaser’s own account only and not with a view to, or for resale in connection with, any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any
present intention to transfer the Shares to any other person or entity. 
 (l)    Purchaser understands that the Shares
have not been registered under the Securities Act by reason of a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

(m)    Purchaser further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available and unless any such disposition is in compliance with Regulation S. Purchaser further acknowledges and understands that the Company is under no
obligation to register the securities. 
 (n)    Purchaser is familiar with the provisions of Rule 144 and
Regulation S (Rules 901 through 905 and the Preliminary Notes thereto), each promulgated under the Securities Act, which, in substance, permits limited public resale of “restricted securities” acquired, directly or indirectly, from the
issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to
whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place
only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of securities be limited in volume and take place only pursuant to brokered transactions. Purchaser further
understands that the Company provides no assurances as to whether Purchaser will be able to sell any or all of the Shares pursuant to Regulation S. Notwithstanding this Section 5(d), Purchaser acknowledges and agrees to the restrictions set
forth in Section 5(e) below. 
 (o)    Purchaser further understands that in the event all of the applicable
requirements of Rule 144 or Regulation S are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144
and Regulation S are not exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to
Rule 144 or Regulation S will have a substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions
do so at their own risk. 
 (p)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result
of Purchaser’s purchase or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying
on the Company for any tax advice. 

  
 -2- 

 (q)    Purchaser hereby acknowledges that Purchaser has received, read, and
understands this Agreement and attachments thereto and agrees to be bound by its terms and conditions, including (without limitation), Section 9 below. Purchaser has signed and understands and confirms the representations made in the Investor
Certificate attached to this Agreement as Exhibit C. 
 5.    Voting Provisions. As
condition precedent to entering into this Agreement, Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to
the terms of the Stockholders Agreement, including the restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

6.    Restrictive Legends and Stop-Transfer Orders. 

(r)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws, including, but not limited to, the
following legends: 
 (i)    “THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON
TRANSFER, INCLUDING ANY APPLICABLE RESALE RESTRICTIONS AND OTHER REQUIREMENTS OF REGULATION S OF THE SECURITIES ACT OF 1933. SUCH TRANSFER RESTRICTIONS ARE BINDING ON TRANSFEREES OF THESE SECURITIES.” 

(ii)    “THE SHARES MAY NOT BE MADE SUBJECT TO HEDGING TRANSACTIONS UNLESS SUCH TRANSACTIONS ARE CONDUCTED IN
COMPLIANCE WITH THE SECURITIES ACT OF 1933, INCLUDING REGULATION S THEREUNDER.” 
 (a)    Stop-Transfer
Notices. Purchaser agrees that, in order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company
transfers its own securities, it may make appropriate notations to the same effect in its own records. 

(b)    Refusal to Transfer. The Company shall not be required (i) to transfer on its books any
Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or other transferee to whom
such Shares shall have been so transferred. 
 7.    No Employment Rights. Nothing in this
Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or without cause. 

  
 -3- 

 8.    Waiver of Statutory Information Rights. Optionee
acknowledges and understands that, but for the waiver made herein, Optionee would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s
stock ledger, a list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the Delaware General Corporation
Law (any and all such rights, and any and all such other rights of Optionee as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the
general public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Optionee hereby unconditionally and irrevocably waives the Inspection
Rights, whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign,
transfer, or cause to be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Optionee in Optionee’s capacity as a stockholder
and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Optionee under any written agreement with the Company. 

9.    Restriction on Transfer of Shares. Notwithstanding any provisions to the contrary, Purchaser shall not
offer or sell any Shares received pursuant to this Agreement in an unregistered transaction to a U.S. Person or for the account or benefit of a U.S. Person prior to the expiration of the one year anniversary (or the
six-month anniversary if the Company is a “reporting issuer,” as defined in Rule 902 under the Securities Act) of the date on which the Shares are issued by the Company under this Agreement. Any
Shares offered or sold prior to the expiration of the one year anniversary (or the six-month anniversary if the Company is a “reporting issuer,” as defined in Rule 902 under the Securities Act) of
the issuance of the Shares may be offered or sold only pursuant to the following conditions: 
 (e)    the purchaser of
the Shares certifies that it is not a U.S. Person and is not acquiring the Shares for the account or benefit of any U.S. Person or is a U.S. Person who purchased the Shares in a transaction that did not require registration under the Securities Act;

 (f)    the purchaser of the Shares agrees to resell such Shares only in accordance with the provisions of Regulation
S, pursuant to registration under the Securities Act, or pursuant to another available exemption or safe harbor from registration under the Securities Act, and agrees not to engage in hedging transactions with regard to the transferred Shares unless
in compliance with the Securities Act; and 
 (g)    the certificate evidencing the Shares shall contain restrictive
legends to a similar effect as described in Subsection (b) of this Section 9. 
 Purchaser further acknowledges that other local
laws applicable to the Shares may prohibit the offer and sale of any Shares received pursuant to this Agreement to other persons and that prior to making any such offer or sale, Purchaser should consult with his or her own personal legal advisor.

  
 -4- 

 10.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or amendment to this
Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of
that provision as to that or any other instance. 
 (d)    Successors and Assigns. Except as
otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal
representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except
with the prior written consent of the Company. 
 (e)    Notices. Any notice, demand or request
required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or
registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most
recent address set forth in the Company’s books and records. 
 (f)    Severability. If one or
more provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such
provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in
accordance with its terms. 

  
 -5- 

 (g)    Construction. This Agreement is the result of
negotiations between and has been reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor
of or against any one of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed
in any number of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the
statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or
otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

  
 -6- 

 The parties have executed this Exercise Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

 

			
	Address:	 	
                     

		
		 	
                     

	
	PURCHASER:
	
	                    
	
	  

	(Signature)
		
	Address:	 	
                     

		
		 	
                     

		
	Email:	 	
                     

  
 -7- 

 I,
                    , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

  
 -8- 

 EXHIBIT C 

Investor Certificate 
 (for
purposes of compliance with Regulation S 
 if you are a foreign national or employed outside the United States) 

In issuing the shares of Common Stock (the “Shares”) of Twist Bioscience Corporation, a Delaware corporation (the “Company”)
pursuant to the Notice of Stock Option Grant and the Stock Option Agreement granted                      and Exercise Agreement made and entered into
as of                      (together, the “Agreement”), the Company intends to rely on Regulation S of the Securities Act (
“Regulation S”) in reliance on the following representations made by the undersigned in connection with the undersigned’s receipt of the Shares: 

1.    The undersigned is not a natural person resident in the United States, a partnership or corporation organized under
the laws of the United States or otherwise a “U.S. Person” (as defined under Regulation S; a copy of such definition is attached hereto) or acting for the benefit or account of a U.S. Person; 

2.    The undersigned understands that the Shares have not been not been registered under the Securities Act; 

3.    The undersigned agrees (a) to resell the Shares only in accordance with the provisions of Regulation S,
pursuant to registration under the Securities Act or pursuant to another available exemption from registration (the availability of such exemption being reflected by an opinion of counsel acceptable to the Company), and (b) not to engage in
hedging transactions with regard to such securities unless in compliance with the Securities Act (including Regulation S thereunder); 

4.    The undersigned understands that a legend will be placed on all certificates evidencing the Shares reflecting the
restrictions upon transfer set forth in paragraph (3) above, and that the Company is required to refuse to register any transfer of securities not made in accordance with the provisions of Regulation S, pursuant to registration under the
Securities Act, or pursuant to an available exemption from registration; and 
 5.    The undersigned agrees not to
offer or sell the Shares to any U.S. Person, or for the account or benefit of a U.S. Person prior to the expiration of the one year anniversary (or the six-month anniversary if the Company is a “reporting
issuer,” as defined in Rule 902 under the Securities Act) of the date on which the Shares underlying the Option were issued by the Company pursuant to the Agreement, unless the Shares are sold in a transaction exempt from the registration
requirements of the Securities Act or pursuant to a registration statement effective under the Securities Act. 
  

							
	Dated:
                                         
                   	 		 	Signature:	 	  

				
		 		 	Print Name:	 	  

  
 -9- 

 Attachment to Investor Certificate 

As defined in Regulation 902(k) of Regulation S under the Securities Act of 1933, as amended, the term “U.S. Person” means: 

 

	 	(i)	any natural person resident in the United States; 

  

	 	(ii)	any partnership or corporation organized or incorporated under the laws of the United States; 

  

	 	(iii)	any estate of which any executor or administrator is a U.S. person; 

  

	 	(iv)	any trust of which any trustee is a U.S. person; 

  

	 	(v)	any agency or branch of a foreign entity located in the United States; 

  

	 	(vi)	any non-discretionary account or similar account (other than an estate or trust) held by a dealer or other fiduciary for the benefit or account of a U.S. person;

  

	 	(vii)	any discretionary account or similar account (other than an estate or trust) held by a dealer or other fiduciary organized, incorporated, or (if an individual) resident in the United States; and 

 

	 	(viii)	any partnership or corporation if: (1) organized or incorporated under the laws of any foreign jurisdiction; and (2) formed by a U.S. person principally for the purpose of investing in securities not
registered under the Securities Act, unless it is organized or incorporated, and owned, by accredited investors (as defined in Rule 501(a) of the Securities Act) who are not natural persons, estates or trusts. 

The following are not U.S. Persons: 
  

	 	(i)	any discretionary account or similar account (other than an estate or trust) held for the benefit or account of a non-U.S. person by a dealer or other professional fiduciary
organized, incorporated, or (if an individual) resident in the United States; 

  

	 	(ii)	any estate of which a professional fiduciary acting as executor or administrator is a U.S. person if: (1) an executor or administrator of the estate who is not a U.S. person has sole or shared investment discretion
with respect to the assets of the estate; and (2) the estate is governed by foreign law; 

  

	 	(iii)	any trust of which any professional fiduciary acting as trustee is a U.S. person, if a trustee who is not a U.S. person has sole or shared investment discretion with respect to the trust assets, and no beneficiary of
the trust (and no settlor if the trust is revocable) is a U.S. person; 

  
 -10- 

	 	(iv)	an employee benefit plan established and administered in accordance with the law of a country other than the United States and customary practices and documentation of such country; 

 

	 	(v)	any agency or branch of a U.S. person located outside the United States if (1) any agency or branch operates for valid business reasons; and (2) the agency or branch is engaged in the business of insurance or
banking and is subject to substantive insurance or banking regulation, respectively, in the jurisdiction where located; and 

  

	 	(vi)	the International Monetary Fund, the International Bank for Reconstruction and Development, the Inter-American Development Bank, the Asian Development Bank, the African Development Bank, the United Nations, and their
agencies, affiliates and pension plans, and any other similar international organizations, their agencies, affiliates and pension plans. 

  
 -11- 

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

RESTRICTED STOCK PURCHASE AGREEMENT 

This Restricted Stock Purchase Agreement (this “Agreement”) is made as of
                     by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”) pursuant to the Company’s 2013 Stock Plan (the “Plan”). To the extent any
capitalized terms used in this Agreement are not defined, they shall have the meaning ascribed to them in the Plan. 

1.    Sale of Stock. Subject to the terms and conditions of this Agreement, on the Purchase Date (as
defined below) the Company will issue and sell to Purchaser, and Purchaser agrees to purchase from the Company,                  shares of the Company’s Common
Stock at a purchase price of $         per share for a total purchase price of $        . The term “Shares” refers to the all of the shares purchased hereunder
and all securities received in connection with the Shares pursuant to stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like, and all new, substituted or
additional securities or other property to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares. By Purchaser’s signature and the signature of the Company’s representative below, Purchaser and the Company agree
that this acquisition of Shares is governed by the terms and conditions of this Agreement and the Twist Bioscience Corporation 2013 Stock Plan which is made a part of this Agreement. As a condition to the delivery of any Shares hereunder, the
Company shall have the right to require that Purchaser become party to the Stockholders Agreement and/or the Registration Rights Agreement. 

2.    Purchase. The purchase and sale of the Shares under this Agreement shall occur at the principal
office of the Company simultaneously with the execution and delivery of this Agreement by the parties, the payment of the aggregate purchase price by any method permitted by the Company and authorized under the Plan, and the satisfaction of any
applicable tax, withholding obligations, required deductions or other payments, all in accordance with the Plan (the “Purchase Date”). The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the purchase price therefor by Purchaser. If applicable, the Company will deliver to Purchaser a
certificate representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws, the Plan the Stockholders Agreement or the Registration Rights Agreement, as the case may be, Purchaser shall not assign, encumber or dispose of any
interest in the Shares while the Shares are subject to the Company’s Repurchase Option (as defined below). After any Shares have been released from such Repurchase Option, Purchaser shall not assign, encumber or dispose of any interest in such
Shares except in compliance with Applicable Laws and the Stockholders Agreement. 

 (a)    Repurchase Option. 

(i)    Without limitation on anything in the Stockholders Agreement and/or the Registration Rights Agreement, as
applicable, in the event of the voluntary or involuntary termination of Purchaser’s Continuous Service Status for any reason (including due to death or Disability or by the Company with or without Cause), the Company shall upon the date of such
termination (the “Termination Date”) have an irrevocable, exclusive option (the “Repurchase Option”) for a period of three months from such date to repurchase all or any portion of the Unvested Shares (as defined
below) held by Purchaser as of the Termination Date at the lesser of (A) the original purchase price per Share (adjusted for any stock splits, stock dividends and the like) specified in Section 1 and (B) the Fair Market Value of such
Shares. As used in this Agreement, “Unvested Shares” means Shares that have not yet been released from the Repurchase Option. 

(ii)    Unless the Company notifies Purchaser within three months from the Termination Date that it does not intend to
exercise its Repurchase Option with respect to some or all of the Unvested Shares, the Repurchase Option shall be deemed automatically exercised by the Company as of the end of such three-month period following such Termination Date, provided that
the Company may notify Purchaser that it is exercising its Repurchase Option as of a date prior to the end of such three-month period. Unless Purchaser is otherwise notified by the Company pursuant to the preceding sentence that the Company does not
intend to exercise its Repurchase Option as to some or all of the Unvested Shares to which it applies at the time of termination, execution of this Agreement by Purchaser constitutes written notice to Purchaser of the Company’s intention to
exercise its Repurchase Option with respect to all Unvested Shares to which such Repurchase Option applies. The Company, at its choice, may satisfy its payment obligation to Purchaser with respect to exercise of the Repurchase Option by either
(A) delivering a check to Purchaser in the amount of the purchase price for the Unvested Shares being repurchased, or (B) in the event Purchaser is indebted to the Company, canceling an amount of such indebtedness equal to the purchase
price for the Unvested Shares being repurchased, or (C) by a combination of (A) and (B) so that the combined payment and cancellation of indebtedness equals such purchase price. In the event of any deemed automatic exercise of the
Repurchase Option pursuant to this Section 3(a)(ii) in which Purchaser is indebted to the Company, such indebtedness equal to the purchase price of the Unvested Shares being repurchased shall be deemed automatically canceled as of the end of
the three-month period following the Termination Date unless the Company otherwise satisfies its payment obligations. As a result of any repurchase of Unvested Shares pursuant to this Section 3(a), the Company shall become the legal and
beneficial owner of the Unvested Shares being repurchased and shall have all rights and interest therein or related thereto, and the Company shall have the right to transfer to its own name the number of Unvested Shares being repurchased by the
Company, without further action by Purchaser. 
 (iii)    100% of the Shares shall initially be subject to the
Repurchase Option (the “Vesting Shares”). [25% of the Vesting Shares shall be released from the Repurchase Option on
                    , and an additional 1/48th of the total Vesting Shares shall be released from the Repurchase Option on the same day of each month
thereafter (and if there is no corresponding day, on the last day of the month)], until all Vesting Shares are released from the Repurchase Option; provided, however, that such scheduled releases from the Repurchase Option shall immediately cease as
of the Termination Date. Fractional shares shall be rounded to the nearest whole share. 

  
 -2- 

 (b)    Assignment. The right of the Company to purchase
any part of the Shares may be assigned in whole or in part to any holder or holders of capital stock of the Company or other persons or organizations. 

(c)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein will
receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, including, insofar as applicable, the Repurchase Option. Any sale or
transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 
 (d)    Lock-Up Agreement. Without limitation on anything in the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters
in connection with the initial public offering of the Company’s securities registered under the Securities Act of 1933, as amended, Purchaser shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to
purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of or otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the
effective date of the relevant registration statement filed under the Securities Act in connection with the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant
registration statement in connection with any other public offering of registrable securities, as such underwriter shall specify reasonably and in good faith. 

4.    Escrow of Unvested Shares. For purposes of facilitating the enforcement of the provisions of
Section 3 above, Purchaser agrees, immediately upon receipt of the certificate(s) for the Shares subject to the Repurchase Option, to deliver such certificate(s), together with an Assignment Separate from Certificate in the form attached to
this Agreement as Exhibit A executed by Purchaser and by Purchaser’s spouse (if required for transfer), in blank, to the Secretary of the Company, or the Secretary’s designee, to hold such certificate(s) and Assignment Separate from
Certificate in escrow and to take all such actions and to effectuate all such transfers and/or releases as are required in accordance with the terms of this Agreement. Purchaser hereby acknowledges that the Secretary of the Company, or the
Secretary’s designee, is so appointed as the escrow holder with the foregoing authorities as a material inducement to make this Agreement and that said appointment is coupled with an interest and is accordingly irrevocable. Purchaser agrees
that said escrow holder shall not be liable to any party hereof (or to any other party). The escrow holder may rely upon any letter, notice or other document executed by any signature purported to be genuine and may resign at any time. Purchaser
agrees that if the Secretary of the Company, or the Secretary’s designee, resigns as escrow holder for any or no reason, the Board shall have the power to appoint a successor to serve as escrow holder pursuant to the terms of this Agreement.

 5.    Investment and Taxation Representations. In connection with the purchase of the Shares,
Purchaser represents to the Company the following: 
 (a)    Purchaser is aware of the Company’s business affairs
and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment

  
 -3- 

 
for Purchaser’s own account only and not with a view to, or for resale in connection with, any “distribution” thereof within the meaning of the Securities Act or under any
applicable provision of state law. Purchaser does not have any present intention to transfer the Shares to any other person or entity. 

(b)    Purchaser understands that the Shares have not been registered under the Securities Act by reason of a specific
exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

(c)    Purchaser further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the securities. 

(d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act, which, in substance,
permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to
the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the
Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of
securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 5(d), Purchaser acknowledges and agrees to the restrictions set forth in Section 5(e) below. 

(e)    Purchaser further understands that in the event all of the applicable requirements of Rule 144 are not satisfied,
registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not exclusive, the Staff of the Securities and Exchange Commission has
expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption from registration
is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result of Purchaser’s purchase
or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying on the Company for any tax
advice. 
 6.    Voting Provisions. As condition precedent to entering into this Agreement,
Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the Stockholders Agreement, including the
restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

  
 -4- 

 7.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

(b)    Stop-Transfer Notices. Purchaser agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in
its own records. 
 (c)    Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or
other transferee to whom such Shares shall have been so transferred. 
 8.    No Employment Rights.
Nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or
without cause. 
 9.    Section 83(b) Election. Purchaser agrees that he will execute and deliver
to the Company with this executed Agreement a copy of the Acknowledgment and Statement of Decision Regarding Section 83(b) Election (the “Acknowledgment”), attached hereto as Exhibit B and, if Purchaser decides to file
an election (an “83(b) Election”) under Section 83(b) of the Internal Revenue Code of 1986, as amended (the “Code”), a copy of the 83(b) Election, attached hereto as Exhibit C. Purchaser further
acknowledges that the Company has directed Purchaser to seek independent advice regarding the applicable provisions of the Code, the income tax laws of any municipality, state or foreign country in which Purchaser may reside, and the tax
consequences of Purchaser’s death. 
 10.    Waiver of Statutory Information Rights. Purchaser
acknowledges and understands that, but for the waiver made herein, Purchaser would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s
stock ledger, a list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the Delaware General Corporation
Law (any and all such rights, and any and all such other rights of Purchaser as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the
general public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Purchaser hereby unconditionally and irrevocably waives the Inspection
Rights, whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign,
transfer, or cause to be commenced any 

  
 -5- 

 
claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Purchaser in Purchaser’s capacity as
a stockholder and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Purchaser under any written agreement with the Company.

 11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted
only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement and the Plan set forth the entire agreement and understanding
of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the subject matter hereof. In the event of any conflict
between the Plan and this Agreement, the Plan will control. 
 (c)    Amendments and Waivers. No
modification of or amendment to this Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this
Agreement shall constitute a waiver of that provision as to that or any other instance. 
 (d)    Successors and
Assigns. Except as otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under
this Agreement, except with the prior written consent of the Company. 
 (e)    Notices. Any
notice, demand or request required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the
U.S. mail as certified or registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on
the signature page, at the most recent address set forth in the Company’s books and records. 

(f)    Severability. If one or more provisions of this Agreement are held to be unenforceable under
applicable law, the parties agree to renegotiate such provision in good faith. 

  
 -6- 

 
In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this Agreement, (ii) the
balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms. 

(g)    Construction. This Agreement is the result of negotiations between and has been reviewed by
each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the parties hereto.

 (h)    Counterparts. This Agreement may be executed in any number of counterparts, each of which
when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. By accepting this Award, Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic
system established and maintained by the Company or a third party designated by the Company. 
 (j)    Imposition
of Other Requirements. The Company reserves the right to impose other requirements on Purchaser’s participation in the Plan and on any Award or Shares acquired under the Plan, to the extent the Company determines it is necessary
or advisable in order to comply with Applicable Law or facilitate the administration of the Plan. Purchaser agrees to sign any additional agreements or undertakings that may be necessary to accomplish the foregoing, including, without limitation,
the Stockholders Agreement and/or the Registration Rights Agreement. Furthermore, Purchaser acknowledges that the laws of the country in which Purchaser is working at the time of grant of this Agreement, the purchase, vesting or sale of Shares
received pursuant to this Agreement (including any rules or regulations governing securities, foreign exchange, tax, labor, or other matters) may subject Purchaser to additional procedural or regulatory requirements that Purchaser is and will be
solely responsible for and must fulfill. 
 (k)    Compliance with Law. If at any the Company or
its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the statutes, rules or regulations of any
applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or otherwise with respect to Shares, and
the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

(l)    Code Section 409A. It is intended that the Shares comply with
or be exempt from Section 409A of the Code, and this Agreement shall be limited, construed and interpreted in accordance with such intent; provided, that for the avoidance of doubt, this provision shall not be construed to require a gross-up payment in respect of any taxes, interest or penalties imposed on the Purchaser as a result of Section 409A of the Code, and by purchasing the Shares pursuant to this Agreement, the Purchaser agrees
and acknowledges that the Company be held liable for any applicable costs, taxes, or penalties associated with the Shares or this Agreement under Code Section 409A or otherwise. 

  
 -7- 

 [Signature Page Follows] 

  
 -8- 

 The parties have executed this Restricted Stock Purchase Agreement as of the date first set forth
above. 
  

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	
                     

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

	
	PURCHASER:
	
	  

	(PRINT NAME)
		
	By:	 	
                     

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

		
	Email:	 	
                     

  
 -9- 

 I,
                    , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

  
 -10- 

 EXHIBIT A 

ASSIGNMENT SEPARATE FROM CERTIFICATE 

FOR VALUE RECEIVED and pursuant to that certain Restricted Stock Purchase Agreement between the undersigned (“Purchaser”) and
Twist Bioscience Corporation, a Delaware corporation (the “Company”), dated                      (the “Agreement”),
Purchaser hereby sells, assigns and transfers unto the Company                     
(                ) shares of the Common Stock of the Company, standing in Purchaser’s name on the Company’s books and represented by Certificate No.
                    , and does hereby irrevocably constitute and appoint
                                         to
transfer said stock on the books of the Company with full power of substitution in the premises. THIS ASSIGNMENT MAY ONLY BE USED AS AUTHORIZED BY THE AGREEMENT AND THE EXHIBITS THERETO. 

 

							
	Dated:
                                        
	 		 	PURCHASER:
			
		 		 	
                     

		 		 	(PRINT NAME)
				
		 		 	By:	 	
                     

		 		 		 	(Signature)
		 		 	Name:	 	
                     

		 		 	Title:	 	
                     

				
		 		 	Address:	 	
                     

				
		 		 		 	
                     

				
		 		 	Email:	 	
                     

			
		 		 	
                     

		 		 	Spouse of Purchaser (if applicable)

 Instructions: Please do not fill in any blanks other than the signature line. The purpose of
this assignment is to enable the Company to exercise its repurchase option set forth in the Agreement without requiring additional signatures on the part of Purchaser. 

 EXHIBIT B 

ACKNOWLEDGMENT AND STATEMENT OF DECISION 

REGARDING SECTION 83(b) ELECTION 
 The
undersigned has entered into a stock purchase agreement with Twist Bioscience Corporation, a Delaware corporation (the “Company”), pursuant to which the undersigned is purchasing
                 shares of Common Stock of the Company (the “Shares”). In connection with the purchase of the Shares, the undersigned hereby represents
as follows: 
 1.    The undersigned has carefully reviewed the stock purchase agreement pursuant to which the
undersigned is purchasing the Shares. 
 2.    The undersigned either [check and complete as applicable]: 

 

	 	(a)	         has consulted, and has been fully advised by, the undersigned’s own tax advisor,
                    , whose business address is
                                        ,
regarding the federal, state and local tax consequences of purchasing the Shares, and particularly regarding the advisability of making elections pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended (the
“Code”) and pursuant to the corresponding provisions, if any, of applicable state law; or 

  

	 	(b)	         has knowingly chosen not to consult such a tax advisor. 

3.    The undersigned hereby states that the undersigned has decided [check as applicable]: 

 

	 	(a)	         to make an election pursuant to Section 83(b) of the Code, and is submitting to the Company, together with the undersigned’s executed stock purchase agreement,
an executed form entitled “Election Under Section 83(b) of the Internal Revenue Code of 1986;” or 

  

	 	(b)	         not to make an election pursuant to Section 83(b) of the Code. 

 4.    Neither the Company nor any subsidiary or representative of the Company
has made any warranty or representation to the undersigned with respect to the tax consequences of the undersigned’s purchase of the Shares or of the making or failure to make an election pursuant to Section 83(b) of the Code or the
corresponding provisions, if any, of applicable state law. 
  

							
	Dated:
                                         
                   	 		 	PURCHASER:
			
		 		 	
                     

		 		 	(PRINT NAME)
			
		 		 	
                     

		 		 	(Signature)
				
		 		 	Address:	 	
                     

				
		 		 		 	
                     

			
		 		 	
                     

		 		 	Spouse of Purchaser (if applicable)

 EXHIBIT C 

ELECTION UNDER SECTION 83(B) 

OF THE INTERNAL REVENUE CODE OF 1986 

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code, to include in taxpayer’s gross
income for the current taxable year, the amount of any compensation taxable to taxpayer in connection with taxpayer’s receipt of the property described below: 
  

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

NAME OF TAXPAYER:
                     
 NAME OF
SPOUSE:                      

ADDRESS:
                                 

IDENTIFICATION NO. OF TAXPAYER:
                     

IDENTIFICATION NO. OF SPOUSE:
                     
 TAXABLE
YEAR:                      
  

	2.	The property with respect to which the election is made is described as follows: 

                 shares of the Common Stock of Twist
Bioscience Corporation, a Delaware corporation (the “Company”). 
  

	3.	The date on which the property was transferred is:                      

 

	4.	The property is subject to the following restrictions: 

 Repurchase option at cost in favor of
the Company upon termination of taxpayer’s employment or consulting relationship, which repurchase option will be released over time subject to the taxpayer’s continued service to the Company. 

 

	5.	The fair market value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms will never lapse, of such property is:
$         per share (or $         in the aggregate). 

  

	6.	The amount (if any) paid for such property: $         per share (or $         in the aggregate). 

The undersigned has submitted a copy of this statement to the person for whom the services were performed in connection with the undersigned’s receipt of
the above-described property. The transferee of such property is the person performing the services in connection with the transfer of said property. 

 The undersigned understands that the foregoing election may not be revoked except with the consent of the
Commissioner. 
  

							
	Dated:                                     
                        	 		 	PURCHASER:
			
		 		 	  

		 		 	(PRINT NAME)
			
		 		 	  

		 		 	(Signature)
				
		 		 	Address:	 	
                     

				
		 		 		 	
                     

			
		 		 	  

		 		 	Spouse of Purchaser (if applicable)

 RECEIPT 

Twist Bioscience Corporation, a Delaware corporation (the “Company”), hereby acknowledges receipt of: 

 

	 	•	 	A check in the amount of $         

 given by
                     as consideration for Common Stock Certificate
                     for                  shares of Common Stock of
the Company. 
  

							
	Dated:                                     
                        	 		 	THE COMPANY:
			
		 		 	TWIST BIOSCIENCE CORPORATION
				
		 		 	By:	 	
                     

		 		 	(Signature)
		 		 	Name:	 	
                     

		 		 	Title:	 	
                     

 RECEIPT AND CONSENT 

The undersigned hereby acknowledges receipt of a photocopy of Common Stock Certificate
                     for                  shares of Common Stock of
Twist Bioscience Corporation, a Delaware corporation (the “Company”). 
 The undersigned further acknowledges that the
Secretary of the Company, or his or her designee, is acting as escrow holder pursuant to the Restricted Stock Purchase Agreement that Purchaser has previously entered into with the Company. As escrow holder, the Secretary of the Company, or his or
her designee, holds the original of the aforementioned certificate issued in the undersigned’s name. 
  

							
	Dated:                                     
                        	 		 	PURCHASER:
			
		 		 	
                    
 

		 		 	(PRINT NAME)
				
		 		 	By:	 	
                     

		 		 	(Signature)
		 		 	Name:	 	
                     

		 		 	Title:	 	
                     

				
		 		 	Address:	 	
                     

				
		 		 		 	
                     

				
		 		 	Email:	 	
                     

			
		 		 	
                     

		 		 	Spouse of Purchaser (if applicable)

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

RESTRICTED STOCK AGREEMENT 

This Restricted Stock Agreement (this “Agreement”) is made as of
                     by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Participant”) pursuant to the Company’s 2013 Stock Plan (the “Plan”). To the extent any
capitalized terms used in this Agreement are not defined, they shall have the meaning ascribed to them in the Plan. 

1.    Grant of Restricted Stock. Subject to the terms and conditions of this Agreement, the Company
hereby grants to Participant                  shares of the Company’s Common Stock (the “Shares”) as consideration for services rendered by
Participant to the Company. The term “Shares” refers to the number of Shares granted and all securities received in connection with the Shares pursuant to stock dividends or splits, all securities received in replacement of the Shares in a
recapitalization, merger, reorganization, exchange or the like, and all new, substituted or additional securities or other property to which Participant is entitled by reason of Participant’s ownership of the Shares. The Company shall issue the
Shares to Participant by entering such Shares in Participant’s name as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company. If applicable, the Company will deliver to
Participant a certificate representing the Shares as soon as practicable following the date hereof. By Participant’s signature and the signature of the Company’s representative below, Participant and the Company agree that this grant of
Shares is governed by the terms and conditions of this Agreement and the Twist Bioscience Corporation 2013 Stock Plan which is made a part of this Agreement. As a condition to the delivery of any Shares hereunder, the Company shall have the right to
require that Participant become party to the Stockholders Agreement and/or the Registration Rights Agreement. 

2.    Vesting Schedule.
                     of the total Shares shall vest on
                    , and an additional
                     of the total Shares shall vest on the corresponding day of each month thereafter (and if there is no corresponding day, the last
day of the month), subject to Participant’s Continuous Service Status through such vesting date. Fractional shares shall be rounded down to the nearest whole share. Shares that have not yet vested as of a given time pursuant to this vesting
schedule are referred to herein as “Unvested Shares.” 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws and the Plan, Participant shall not assign, encumber or dispose of any interest in the Shares while the Shares are unvested and subject to
forfeiture, as described below. After any Shares have vested and are no longer subject to forfeiture as described below, Participant shall not assign, encumber or dispose of any interest in such Shares except in compliance with the Stockholders
Agreement. 
 (a)    Forfeiture Upon Termination of Participant’s Continuous Service Status.
Notwithstanding any contrary provision of this Agreement, in the event of any voluntary or involuntary termination of Participant’s Continuous Service Status prior to vesting pursuant to 

 
the Vesting Schedule set forth in Section 2 above for any reason (including due to death or Disability or by the Company with or without Cause), the then Unvested Shares will thereupon be
forfeited and automatically transferred to and reacquired by the Company at no cost to the Company upon the date of such termination and Participant will have no further rights or interests with respect to such Unvested Shares. 

(b)    Restrictions Binding on Transferees. All transferees of Shares or any interest therein will
receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, including, insofar as applicable, the forfeiture provision in
Section 3(a) above. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

(c)    Lock-Up Agreement. Without limitation on anything in
the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters in connection with the initial public offering of the Company’s securities registered under the
Securities Act of 1933, as amended, Participant shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of or
otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the effective date of the relevant registration statement filed under the Securities Act in connection with
the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant registration statement in connection with any other public offering of registrable securities, as such
underwriter shall specify reasonably and in good faith. 
 4.    Escrow of Unvested Shares. For
purposes of facilitating the enforcement of the provisions of Section 3(a) above, Participant agrees, immediately upon receipt of the stock certificate or, in the case of uncertificated securities, notice of issuance, for the Unvested Shares,
to deliver any such stock certificate(s), as well as a Stock Power in the form attached to this Agreement as Attachment A executed by Participant and by Participant’s spouse (if required for transfer), in blank, to the
Secretary of the Company, or the Secretary’s designee, to hold such Shares (and such stock certificate(s), if any) and Stock Power in escrow and to take all such actions and to effectuate all such transfers and/or releases as are required in
accordance with the terms of this Agreement. Participant hereby acknowledges that the Secretary of the Company, or the Secretary’s designee, is so appointed as the escrow holder with the foregoing authorities as a material inducement to make
this Agreement and that said appointment is coupled with an interest and is accordingly irrevocable. Participant agrees that said escrow holder shall not be liable to any party hereof (or to any other party). The escrow holder may rely upon any
letter, notice or other document executed by any signature purported to be genuine and may resign at any time. Participant agrees that if the Secretary of the Company, or the Secretary’s designee, resigns as escrow holder for any or no reason,
the Board shall have the power to appoint a successor to serve as escrow holder pursuant to the terms of this Agreement. 

 5.    Investment and Taxation Representations. In
connection with the receipt of the Shares, Participant represents to the Company the following: 
 (a)    Participant is
aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Participant is receiving the Shares for investment
for Participant’s own account only and not with a view to, or for resale in connection with, any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Participant does not have
any present intention to transfer the Shares to any other person or entity. 
 (b)    Participant understands that the
Shares have not been registered under the Securities Act by reason of a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Participant’s investment intent as expressed herein. 

(c)    Participant further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available. Participant further acknowledges and understands that the Company is under no obligation to register the securities. 

(d)    Participant is familiar with the provisions of Rule 144, promulgated under the Securities Act, which, in substance,
permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to
the satisfaction of certain conditions. Participant understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the
Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of
securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 5(d), Participant acknowledges and agrees to the restrictions set forth in Section 5(e) below. 

(e)    Participant further understands that in the event all of the applicable requirements of Rule 144 are not satisfied,
registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not exclusive, the Staff of the Securities and Exchange Commission has
expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption from registration
is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Participant understands that Participant may suffer adverse tax consequences as a result of Participant’s
receipt or disposition of the Shares. Participant represents that Participant has consulted any tax consultants Participant deems advisable in connection with the receipt or disposition of the Shares and that Participant is not relying on the
Company for any tax advice. 
 6.    Voting Provisions. As condition precedent to entering into
this Agreement, Participant shall become a party to the Stockholders Agreement as an “Other Stockholder” by 

 
executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the Stockholders Agreement, including the restrictions on transfer contained therein,
and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

7.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

(b)    Stop-Transfer Notices. Participant agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in
its own records. 
 (c)    Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or
other transferee to whom such Shares shall have been so transferred. 
 8.    No Employment Rights.
Nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Participant’s employment or consulting relationship, for any reason, with
or without cause. 
 9.    Section 83(b) Election. Participant understands that Section 83(a)
of the Internal Revenue Code of 1986, as amended (the “Code”), taxes as ordinary income the difference between the amount paid, if any, for the Shares and the Fair Market Value of the Shares as of each vesting date. Participant
understands that Participant may elect to be taxed at the time the Shares are granted, rather than when such Shares vest, by filing an election under Section 83(b) (an “83(b) Election”) of the Code with the Internal Revenue
Service within thirty (30) days from the date of grant of the restricted stock award. Even if the Fair Market Value of the Shares at the time of the execution of this Agreement equals the amount paid for the Shares, the election must be made to
avoid income under Section 83(a) in the future. Participant understands that failure to file such an election in a timely manner may result in adverse tax consequences for Participant. Participant further understands that an additional copy of
such election form should be filed with Participant’s federal income tax return for the calendar year in which the date of this Agreement falls. Participant acknowledges that the foregoing is only a summary of the effect of United States
federal income taxation with respect to grant of the Shares hereunder, does not purport to be complete, and is not intended or written to be used, and cannot be used, for the purposes of avoiding taxpayer penalties. Participant further acknowledges
that the Company has directed Participant to seek independent advice regarding the applicable provisions of the Code, the income tax laws of any municipality, state or foreign country in which Participant may reside, and the tax consequences of
Participant’s death, and Participant has consulted, and has been fully advised by, 

 
Participant’s own tax advisor regarding such tax laws and tax consequences or has knowingly chosen not to consult such a tax advisor. Participant further acknowledges that neither the
Company nor any subsidiary or representative of the Company has made any warranty or representation to Participant with respect to the tax consequences of Participant’s receipt of the Shares or of the making or failure to make an 83(b)
Election. PARTICIPANT (AND NOT THE COMPANY, ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR APPROPRIATELY FILING SUCH FORM WITH THE IRS, EVEN IF PARTICIPANT REQUESTS THE COMPANY, ITS AGENTS OR ANY OTHER PERSON MAKE THIS FILING ON
PARTICIPANT’S BEHALF. 
 Participant agrees that Participant will execute and deliver to the Company with this executed Agreement a
copy of the Acknowledgment and Statement of Decision Regarding Section 83(b) Election (the “Acknowledgment”), attached hereto as Attachment B and, if Participant decides to make an 83(b) Election, a
copy of the 83(b) Election, attached hereto as Attachment C. 
 10.    Waiver of
Statutory Information Rights. Participant acknowledges and understands that, but for the waiver made herein, Participant would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose,
and to make copies and extracts from, the Company’s stock ledger, a list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided
in Section 220 of the General Corporation Law of Delaware (any and all such rights, and any and all such other rights of Participant as may be provided for in Section 220, the “Inspection Rights”). In light of the
foregoing, until the first sale of Common Stock of the Company to the general public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended,
Participant hereby unconditionally and irrevocably waives the Inspection Rights, whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to
directly or indirectly commence, voluntarily aid in any way, prosecute, assign, transfer, or cause to be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to
the Inspection Rights of Participant in Participant’s capacity as a stockholder and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual
inspection rights of Participant under any written agreement with the Company. 

11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted
only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

 (b)    Entire Agreement. This Agreement and the Plan set
forth the entire agreement and understanding of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the subject
matter hereof. In the event of any conflict between the Plan and this Agreement, the Plan will control. 

(c)    Amendments and Waivers. No modification of or amendment to this Agreement, nor any waiver of
any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall constitute a waiver of that provision as to that or
any other instance. 
 (d)    Successors and Assigns. Except as otherwise provided in this
Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors, administrators and legal representatives. The Company may
assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under this Agreement, except with the prior written consent of
the Company. 
 (e)    Notices. Any notice, demand or request required or permitted to be given
under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the U.S. mail as certified or registered mail with postage prepaid,
addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on the signature page, at the most recent address set forth in the
Company’s books and records. 
 (f)    Severability. If one or more provisions of this
Agreement are held to be unenforceable under Applicable Law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then
(i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its
terms. 
 (g)    Construction. This Agreement is the result of negotiations between and has been
reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the
parties hereto. 
 (h)    Counterparts. This Agreement may be executed in any number of
counterparts, each of which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. Execution of a facsimile or scanned copy will have the same force and effect as execution
of an original, and a facsimile or scanned signature will be deemed an original and valid signature. 

 (i)    Electronic Delivery. The Company may, in its sole
discretion, decide to deliver any documents related to this Agreement or any notices required by applicable law or the Company’s Certificate of Incorporation or Bylaws by email or any other electronic means. Participant hereby consents to
(i) conduct business electronically (ii) receive such documents and notices by such electronic delivery and (iii) sign documents electronically and agrees to participate through an on-line or
electronic system established and maintained by the Company or a third party designated by the Company. 

(j)    Compliance with Law. If at any the Company or its counsel shall be of the opinion that any
sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the statutes, rules or regulations of any applicable jurisdiction, the Company shall
have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or otherwise with respect to Shares, and the right to purchase Shares shall be
suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the Company. 

[Signature Page Follows] 

 The parties have executed this Restricted Stock Agreement as of the date first set forth above.

  

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

 

			
	Address:	 	  

		
		 	  

 

			
	PARTICIPANT:
	
	  

	(PRINT NAME)
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

 

			
	Address:	 	  

		
		 	  

		
	Email:	 	  

 I,
                    , spouse of
                     (“Participant”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to receive the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall hereby
be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise or waiver of any rights under the
Agreement. 
  

	
	  

	Spouse of Participant (if applicable)

 ATTACHMENT A 

STOCK POWER 
 FOR
VALUE RECEIVED, the undersigned (“Holder”), hereby sells, assigns and transfers unto
                                         
                    (“Transferee”)                  shares
of the Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), standing in Holder’s name on the Company’s books as Certificate No.
CS-                     whether held in certificated or uncertificated form, and does hereby irrevocably
constitute and appoint
                                         to
transfer said stock on the books of the Company with full power of substitution in the premises. 
  

							
	Dated:
                                         
                   	 		 		 	HOLDER:
				
		 		 		 	  

		 		 		 	(PRINT NAME)
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Holder (if applicable)

 This Stock Power may only be used as authorized by the Restricted Stock Agreement between the Holder and the
Company, dated                      and the exhibits thereto. 

Instructions: Please do not fill in any blanks other than the signature line. The purpose of this Stock Power is to enable the
Company to transfer the Unvested Shares to the Company upon termination of Holder’s Continuous Service Status without requiring additional signatures on the part of Holder. 

 IF YOU WISH TO MAKE A SECTION 83(B) 

ELECTION, THE FILING OF SUCH ELECTION 

IS YOUR RESPONSIBILITY. 
 THE FORM
FOR MAKING THIS SECTION 83(B) 
 ELECTION IS ATTACHED TO THIS 

AGREEMENT. 
 YOU MUST FILE THIS
FORM WITHIN 30 DAYS 
 OF PURCHASING THE SHARES. 

YOU (AND NOT THE COMPANY, ANY OF ITS 

AGENTS OR ANY OTHER PERSON) SHALL BE 

SOLELY RESPONSIBLE FOR FILING SUCH 

FORM WITH THE IRS, EVEN IF YOU REQUEST 

THE COMPANY, ITS AGENTS OR ANY OTHER 

PERSON TO MAKE THIS FILING ON YOUR 

BEHALF AND EVEN IF THE COMPANY, ANY 

OF ITS AGENTS OR ANY OTHER PERSON HAS 

PREVIOUSLY MADE THIS FILING ON YOUR 

BEHALF. 

 ATTACHMENT B 

ACKNOWLEDGMENT AND STATEMENT OF DECISION 

REGARDING SECTION 83(b) ELECTION 
 The
undersigned has entered into a restricted stock agreement with Twist Bioscience Corporation, a Delaware corporation (the “Company”), pursuant to which the undersigned has been granted
                 shares of Common Stock of the Company (the “Shares”). In connection with the receipt of the Shares, the undersigned hereby represents
as follows: 
 1.    The undersigned has carefully reviewed the restricted stock agreement pursuant to which the
undersigned is receiving the Shares. 
 2.    The undersigned either [check and complete as applicable]: 

 

	 	(a)	         has consulted, and has been fully advised by, the undersigned’s own tax advisor,
                                        , whose
business address is
                                         
                   , regarding the federal, state and local tax consequences of receiving the Shares, and particularly regarding the advisability of making
elections pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended (the “Code”) and pursuant to the corresponding provisions, if any, of applicable state law; or 

 

	 	(b)	        has knowingly chosen not to consult such a tax advisor. 

3.    The undersigned hereby states that the undersigned has decided [check as applicable]: 

 

	 	(a)	         to make an election pursuant to Section 83(b) of the Code, and is submitting to the Company, together with the undersigned’s executed restricted stock
agreement, an executed form entitled “Election Under Section 83(b) of the Internal Revenue Code of 1986;” or 

  

	 	(b)	         not to make an election pursuant to Section 83(b) of the Code. 

4.    Neither the Company nor any subsidiary or representative of the Company has made any warranty or representation to
the undersigned with respect to the tax consequences of the undersigned’s receipt of the Shares or of the making or failure to make an election pursuant to Section 83(b) of the Code or the corresponding provisions,
if any, of applicable state law. 
  

					
	Dated:
                                         
                   	 		 	PARTICIPANT:
			
		 		 	  

		 		 	(PRINT NAME)
			
		 		 	  

		 		 	(Signature)
			
		 		 	  

		 		 	Spouse of Participant (if applicable)

 ATTACHMENT C 

ELECTION UNDER SECTION 83(B) 

OF THE INTERNAL REVENUE CODE OF 1986 

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code, to include in taxpayer’s gross
income for the current taxable year, the amount of any compensation taxable to taxpayer in connection with taxpayer’s receipt of the property described below: 
  

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

NAME OF TAXPAYER:
                     
 NAME OF
SPOUSE:                      

ADDRESS:
                                 

IDENTIFICATION NO. OF TAXPAYER:
                     

IDENTIFICATION NO. OF SPOUSE:
                     
 TAXABLE
YEAR:                      
  

	2.	The property with respect to which the election is made is described as follows: 

                     shares of the
Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”). 
  

	3.	The date on which the property was transferred is:                      

 

	4.	The property is subject to the following restrictions: 

 The Shares may not be transferred and
are subject to forfeiture under the terms of an agreement between the taxpayer and the Company. These restrictions lapse upon the satisfaction of certain conditions contained in such agreement, including continued service. 

 

	5.	The fair market value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms will never lapse, of such property is: USD
$        . 

  

	6.	The amount (if any) paid for such property: USD $        . 

 The
undersigned has submitted a copy of this statement to the person for whom the services were performed in connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the
services in connection with the transfer of said property. 

 The undersigned understands that the foregoing election may not be revoked except with the consent of the
Commissioner. 
  

					
	Dated:
                                         
                   	 		 	PARTICIPANT:
			
		 		 	  

		 		 	(Signature)
			
		 		 	  

		 		 	Spouse of Participant (if applicable)

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

NOTICE OF STOCK OPTION GRANT 
  

                     

 

			
	Address:	 	                                
		 	                                

 You have been granted an Option to purchase Shares of Common Stock of Twist Bioscience Corporation, a Delaware
corporation (the “Company”), as provided in this Notice of Stock Option Grant (this “Notice”) and subject to the terms and conditions of the Twist Bioscience Corporation 2013 Stock Plan and its Israeli Addendum (the
“Plan”) and the Stock Option Agreement attached hereto, all of which are made a part of this Notice. Unless otherwise defined in this Notice, capitalized terms used but not defined in this Notice shall have the meanings defined in
the Plan. 
  

			
	Date of Grant:	  	
		
	Total Number of Shares:	  	
		
	Exercise Price per Share:	  	
		
	 Designation of Option:
	  	
		
		  	 Israeli Tax Status
  

         102 Capital Gain Track Award

         102 Ordinary Income Track Award

         102 Non-Trustee Award

         3(9) Award

		
	Expiration Date:	  	
		
	Vesting Commencement Date:	  	
		
	Exercise Schedule:	  	The Option is immediately exercisable as to all Shares underlying this Option.
		
	Vesting Schedule:	  	So long as your Continuous Service Status does not terminate, the Shares underlying this Option shall vest in accordance with the following schedule: [12/48th of the Total
Number of Shares shall vest on the one year anniversary of the Vesting Commencement Date, and 1/48th of the Total Number of Shares shall vest on the same day of each month thereafter (and if there
is no corresponding day, on the last day of the month).]

 
			
	Termination Period:	  	You may exercise this Option for 3 month(s) after termination of your Continuous Service Status, except as otherwise provided in Section 5 of the Stock Option Agreement (but in no event later than the Expiration Date). You
are responsible for keeping track of these exercise periods following the termination of your Continuous Service Status for any reason. The Company will not provide further notice of such periods.

 By your signature and the signature of the Company’s representative below, you and the Company
agree that this Option is granted under and governed by the terms and conditions of this Notice, the Plan and the Stock Option Agreement. Further, as a condition to the grant of this Option and/or the delivery of any Shares upon the vesting or
exercise of this Option, the Company shall have the right to require that you become party to the Stockholders Agreement and/or the Registration Rights Agreement. 

In addition, you agree and acknowledge that your rights to any Shares underlying this Option will be earned only as you provide services to
the Company over time, that the grant of this Option is not as consideration for services you rendered to the Company prior to your date of hire, and that nothing in this Notice or the attached documents confers upon you any right to continue your
employment or consulting relationship with the Company for any period of time, nor does it interfere in any way with your right or the Company’s right to terminate that relationship at any time, for any reason, with or without cause. For
purposes of this paragraph, the term “Company” will be interpreted to include any Parent, Subsidiary or Affiliate. 
 To the
extent the Option is designated above as either a 102 Capital Gain Track Award or a 102 Ordinary Income Track Award, the Optionee declares and acknowledges that he or she: (i) fully understands that Section 102 applies to the Option
specified in this Notice; and (ii) understands the provisions of Section 102, the tax track chosen and the implications thereof. In addition, the terms of the Option shall also be subject to the terms of the Trust Agreement between the
Company and the Trustee, as well as the requirements of the Israeli Income Tax Commissioner. The grant of the Option is conditioned upon the Optionee signing all documents requested by the Company, the Affiliate or the Trustee, in accordance with
the Trust Agreement. A copy of the Trust Agreement is available for the Optionee’s review, during normal working hours at his or her Affiliate’s offices. 

[Signature Page Follows] 

 
			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
		
	Name:	 	  

	Title:	 	  

	
	OPTIONEE:
	
	  

			
	(Signature)	 	

 
			
		
	Address:	 	  

		 	  

 TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

STOCK OPTION AGREEMENT 

1.    Grant of Option. Twist Bioscience Corporation, a Delaware corporation (the
“Company”), hereby grants to                      (“Optionee”), an option (the “Option”) to
purchase the total number of shares of Common Stock (the “Shares”) set forth in the Notice of Stock Option Grant (the “Notice”), at the exercise price per Share set forth in the Notice (the “Exercise
Price”) subject to the terms, definitions and provisions of the Twist Bioscience Corporation 2013 Stock Plan and its Israeli Addendum (the “Plan”) adopted by the Company, which is incorporated in this Stock Option Agreement
(this “Agreement”) by reference. Unless otherwise defined in this Agreement, the terms used in this Agreement or the Notice shall have the meanings defined in the Plan. 

2.    Designation of Option. This Option is intended to be an Incentive Stock Option as defined in
Section 422 of the Code only to the extent so designated in the Notice, and to the extent it is not so designated, or to the extent this Option does not or ceases to qualify as an Incentive Stock Option, it shall be treated as a Nonstatutory
Stock Option. 
 Notwithstanding the above, if designated as an Incentive Stock Option, in the event that the Shares subject to this Option
(and all other incentive stock options granted to Optionee by the Company or any Parent or Subsidiary, including under other plans) that first become exercisable in any calendar year have an aggregate Fair Market Value (determined for each Share as
of the date of grant of the option covering such Share) in excess of $100,000, this Option, to the extent the value thereof is in excess of $100,000, shall be treated as a Nonstatutory Stock Option, in accordance with Section 7(c) of the Plan.

 Notwithstanding anything to the contrary, including the indication under “Designation of Option” above, the Company or the
Affiliate shall be under no duty to ensure, and no representation or commitment is made by the Company or the Affiliate, as the case may be, that this Option qualifies or will qualify under any particular tax treatment (such as Section 102 or
any other treatment), nor shall the Company or the Affiliate be required to take any action for the qualification of any Option under such tax treatment. The Company or the Affiliate shall have no liability of any kind or nature in the event that,
for any reason whatsoever, this Option does not qualify for any particular tax treatment. 
 3.    Exercise of
Option. This Option shall be exercisable during its term in accordance with the Exercise Schedule set out in the Notice and with the provisions of Section 7(c) of the Plan as follows: 

(a)    Right to Exercise. 

(i)    This Option may not be exercised for a fraction of a share. 

 (ii)    In the event of Optionee’s death, Disability or other
termination of Continuous Service Status, the exercisability of this Option is governed by Section 5 below, subject to the limitations contained in this Section 3. 

(iii)    In no event may this Option be exercised after the Expiration Date set forth in the Notice. 

(b)    Method of Exercise. 

(i)    This Option shall be exercisable by execution and delivery of the Early Exercise Notice and Restricted Stock
Purchase Agreement attached hereto as Exhibit A, the Exercise Agreement attached hereto as Exhibit B or of any other form of written notice approved for such purpose by the Company which shall state Optionee’s election to exercise
this Option, the number of Shares in respect of which this Option is being exercised, and such other representations and agreements as to the holder’s investment intent with respect to such Shares as may be required by the Company pursuant to
the provisions of the Plan. Such written notice shall be signed by Optionee and shall be delivered to the Company by such means as are determined by the Company in its discretion to constitute adequate delivery. The written notice shall be
accompanied by payment of the aggregate Exercise Price for the purchased Shares. 
 (ii)    As a condition to the
exercise of this Option and subject to Section 9 of the Plan, Optionee agrees to make adequate provision for federal, state, Israeli or other applicable tax, withholding, required deductions or other payments, if any, which arise upon the
grant, vesting or exercise of this Option, or disposition of Shares, whether by withholding, direct payment to the Company, or otherwise, as determined by the Company in its sole discretion. 

(iii)    The Company is not obligated, and will have no liability for failure, to issue or deliver any Shares upon
exercise of this Option unless such issuance or delivery would comply with the Applicable Laws, with such compliance determined by the Company in consultation with its legal counsel. This Option may not be exercised until such time as the Plan has
been approved by the holders of capital stock of the Company, or if the issuance of such Shares upon such exercise or the method of payment of consideration for such Shares would constitute a violation of any Applicable Laws, including any
applicable U.S. federal or state securities laws or any other law or regulation, including any rule under Part 221 of Title 12 of the Code of Federal Regulations as promulgated by the Federal Reserve Board. As a condition to the exercise
of this Option, the Company may require Optionee to make any representation and warranty to the Company as may be required by the Applicable Laws. Assuming such compliance, for income tax purposes the Shares shall be considered transferred to
Optionee on the date on which this Option is exercised with respect to such Shares. 
 (iv)    With respect to 102
Trustee Award, the Shares issued upon exercise of such 102 Trustee Award shall be issued to and in the name of the Trustee on behalf of Optionee, and shall be held by the Trustee in trust on behalf of Optionee; provided, however, that in the
event the Optionee elects to receive the Shares directly to his/her possession, the transfer from the Trustee shall be subject to the payment of any and all applicable taxes by the Optionee, to the satisfaction of each of the Trustee and the
Company, until the full payment of required taxes, as applicable. 

 (v)    Subject to compliance with Applicable Laws, this Option shall be
deemed to be exercised upon receipt by the Company of the appropriate written notice of exercise accompanied by the Exercise Price and the satisfaction of any applicable obligations described in Section 3(b)(ii) above. 

4.    Method of Payment. Payment of the Exercise Price shall be by cash or check or, following the
initial public offering of the Company’s Common Stock and subject to the receipt of any required tax ruling, if applicable, by Cashless Exercise pursuant to which the Optionee delivers an irrevocable direction to a securities broker (on a form
prescribed by the Company and according to a procedure established by the Company).1 

5.    Termination of Relationship. Following the date of termination of Optionee’s Continuous
Service Status for any reason (the “Termination Date”), Optionee may exercise this Option only as set forth in the Notice and this Section 5. If Optionee does not exercise this Option within the Termination Period set forth in
the Notice or the termination periods set forth below, this Option shall terminate in its entirety. In no event, may any Option be exercised after the Expiration Date of this Option as set forth in the Notice. 

(a)    General Termination. In the event of termination of Optionee’s Continuous Service Status
other than as a result of Optionee’s Disability or death or Optionee’s termination by the Company for Cause, Optionee may, to the extent Optionee is vested in the Optioned Stock at the date of such termination, exercise this Option during
the Termination Period set forth in the Notice (but in no event later than the Expiration Date). 

(b)    Termination upon Disability of Optionee. In the event of termination of Optionee’s
Continuous Service Status as a result of Optionee’s Disability, Optionee may, but only within 12 month(s) following the Termination Date, exercise this Option to the extent Optionee is vested in the Optioned Stock. 

(c)    Death of Optionee. In the event of termination of Optionee’s Continuous Service Status as
a result of Optionee’s death, or in the event of Optionee’s death within 3 month(s) following Optionee’s Termination Date, this Option may be exercised at any time within 12 month(s) following the Termination Date, or if later, 12
month(s) following the date of death (but in each case, in no event later than the Expiration Date) by any beneficiaries designated in accordance with Section 16 of the Plan or, if there are no such beneficiaries, by the Optionee’s estate,
or by a person who acquired the right to exercise the Option by bequest or inheritance, but only to the extent Optionee is vested in this Option. 

(d)    Termination for Cause. In the event of termination of Optionee’s Continuous Service
Status by the Company for Cause, this Option (including any vested portion thereof) shall immediately terminate in its entirety upon first notification to Optionee of such termination by the Company for Cause. If Optionee’s Continuous Service
Status is suspended pending an investigation of whether Optionee’s Continuous Service Status will be terminated by the Company for Cause, all Optionee’s rights under this Option, including the right to exercise this Option, shall be
suspended during the investigation period. 
  

	1 Note:	Any cashless exercise (i.e., the surrender of shares having a fair market value equal to the exercise price) of a 102 Trustee Award is subject to the ITA’s pre-approval. 

 6.    Non-Transferability of
Option. This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised during the lifetime of Optionee only by him or her, subject to the terms of the Plan and
the Stockholders Agreement. The terms of this Option shall be binding upon the executors, administrators, heirs, successors and assigns of Optionee. With respect to 102 Trustee Award, Optionee shall not sell, assign, transfer, pledge, give as a
collateral, or grant any right to any third party or release from trust any Option and any Share received and/or any additional rights, including bonus shares that may be distributed to the Optionee in connection with such 102 Trustee Award (the
“Additional Rights”), which will be allocated to the Trustee on behalf of the Optionee and shall be held in trust or controlled by the Trustee for the benefit of the Optionee, until at least the lapse of the Required Holding
Period. Notwithstanding the above, if any such sale or release occurs during the Required Holding Period, the sanctions under Section 102 shall apply to and shall be borne by the Optionee. At the end of the Required Holding Period, the Options
or Shares underlying the Options or any Additional Rights may be transferred to the Optionee upon his or her demand, but only under the condition that the tax due in accordance with Section 102 is paid to the satisfaction of the Trustee and the
Company. With respect to any Award granted by the Company pursuant to Section 102(c) of the Ordinance (which provides for ordinary income Awards administered by the Trustee), the Award and all rights (if any) that accrue thereon shall be
allocated or issued to the Trustee, who shall hold such Award and all rights accrued thereon (if any) in trust for the benefit of the Optionee and/or the Company, as the case may be, until the full payment of required taxes arising from such Award
and/or rights accrued thereon (if any). 
 7.    Lock-Up
Agreement. Without limitation on anything in the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, to the extent so requested by the Company or the underwriters in connection with the initial public
offering of the Company’s securities registered under the Securities Act of 1933, as amended, Optionee shall not directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to
sell, grant any option, right or warrant for the sale of or otherwise dispose of or transfer any shares held by it for such period, not to exceed (a) one hundred eighty (180) days following the effective date of the relevant registration
statement filed under the Securities Act in connection with the Company’s initial public offering of registrable securities, or (b) ninety (90) days following the effective date of the relevant registration statement in connection with any
other public offering of registrable securities, as such underwriter shall specify reasonably and in good faith. 

8.    Tax Consultation. The Optionee is advised to consult with a tax advisor with respect to the tax
consequences of exercising the Option hereunder or disposing of the Shares issued upon exercise of the Options. The Company does not assume any responsibility to advise the Optionee on such matters, which shall remain solely the responsibility of
the Optionee. 
 9.    Irrevocable Proxy. As a material precondition to the Company’s grant of
Options and issuance of Shares in accordance with the Plan, the Optionee hereby executes an irrevocable proxy in the form attached hereto as Exhibit C (and, if applicable, instructs the Trustee to sign such proxy, as requested by the
Company), to the Company which shall designate such person or 

 
persons (with a right of substitution) from time to time as determined by the Administrator (and in the absence of such determination, the CEO or Chairman of the Board, ex officio). The
provisions of this Section shall apply to the Optionee and to any purchaser, assignee or transferee of any Shares. 

10.    Effect of Agreement. Optionee acknowledges receipt of a copy of the Plan and represents that
he or she is familiar with the terms and provisions thereof (and has had an opportunity to consult counsel regarding the Option terms), and hereby accepts this Option and agrees to be bound by its contractual terms as set forth herein and in the
Plan. Optionee hereby agrees to accept as binding, conclusive and final all decisions and interpretations of the Administrator regarding any questions relating to this Option. In the event of a conflict between the terms and provisions of the Plan
and the terms and provisions of the Notice and this Agreement, the Plan terms and provisions shall prevail. 

11.    Imposition of Other Requirements. The Company reserves the right to impose other requirements
on Optionee’s participation in the Plan, on the Option and on any Award or Shares acquired under the Plan, to the extent the Company determines it is necessary or advisable in order to comply with Applicable Laws or facilitate the
administration of the Plan. Optionee agrees to sign any additional agreements or undertakings that may be necessary to accomplish the foregoing, including, without limitation, the Stockholders Agreement and/or the Registration Rights Agreement.
Furthermore, Optionee acknowledges that the laws of the country in which Optionee is working at the time of grant, vesting and exercise of the Option or the sale of Shares received pursuant to this Agreement (including any rules or regulations
governing securities, foreign exchange, tax, labor, or other matters) may subject Optionee to additional procedural or regulatory requirements that Optionee is and will be solely responsible for and must fulfill. 

12.    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to Optionee’s current or future participation in the Plan by electronic means or to request Optionee’s consent to participate in the Plan by electronic means. By accepting this Option grant, Optionee hereby consents to receive such
documents by electronic delivery and subject to the receipt of any required tax ruling, if applicable, agrees to participate in the Plan through an on-line or electronic system established and maintained by
the Company or a third party designated by the Company. [Note: With respect to Options granted under Section 102 of the Ordinance, an electronic signature must be approved by the ITA in advance.] 

13.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of Delaware, without giving effect to principles of conflicts of
law; provided that with respect to any Option granted under Israeli law the tax treatment and the tax rules and regulations applying hereto shall be the Ordinance. For purposes of litigating any dispute that may arise directly or indirectly
from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located
in Delaware and no other courts. 

 (b)    Entire Agreement. This Agreement, together with
the Plan and the Notice, set forth the entire agreement and understanding of the parties relating to the subject matter herein and supersede all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between
them relating to the subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or
amendment to this Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall
constitute a waiver of that provision as to that or any other instance. 
 (d)    Successors and
Assigns. Except as otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under
this Agreement, except with the prior written consent of the Company. 
 (e)    Notices. Any
notice, demand or request required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the
U.S. mail as certified or registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on
the signature page, at the most recent address set forth in the Company’s books and records. 

(f)    Severability. If one or more provisions of this Agreement are held to be unenforceable under
applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this
Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms. 

(g)    Construction. This Agreement is the result of negotiations between and has been reviewed by
each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the parties hereto.

 (h)    Counterparts. This Agreement may be executed in any number of counterparts, each of which
when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Code Section 409A. It is intended that the Option comply with or be
exempt from Section 409A of the Code, and this Agreement shall be limited, construed and interpreted in accordance with such intent; provided, that for the avoidance of doubt, this provision shall not be construed to require a gross-up payment in respect of any taxes, interest or penalties 

 
imposed on the Optionee as a result of Section 409A of the Code, and by accepting this Option grant, the Optionee agrees and acknowledges that the Company be held liable for any applicable
costs, taxes, or penalties associated with this Option or this Agreement under Code Section 409A or otherwise. 

 EXHIBIT A 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EARLY EXERCISE NOTICE AND RESTRICTED STOCK PURCHASE AGREEMENT 

This Agreement (“Agreement”) is made as of
                     by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan and its Israeli Addendum (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). Of these Shares,
Purchaser has elected to purchase                      of those Shares which have become vested as of the date hereof under the Vesting Schedule set
forth in the Notice of Stock Option Grant (the “Vested Shares”) and                  Shares which have not yet vested under such Vesting Schedule (the
“Unvested Shares”). The purchase price for the Shares shall be $0.00001 per Share for a total purchase price of $        . The term “Shares” refers to the purchased Shares and
all securities received in connection with the Shares pursuant to stock dividends or splits, all securities received in replacement of the Shares in a recapitalization, merger, reorganization, exchange or the like, and all new, substituted or
additional securities or other property to which Purchaser is entitled by reason of Purchaser’s ownership of the Shares. 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. With respect to 102 Trustee Award, the Shares issued upon
exercise of such 102 Trustee Award shall be issued to and in the name of the Trustee on behalf of Optionee, and shall be held by the Trustee in trust on behalf of Optionee. If applicable, the Company will deliver to Purchaser a certificate
representing the Shares as soon as practicable following such date. 
 3.    Limitations on
Transfer. In addition to any other limitation on transfer created by Applicable Laws, the Plan and the Option Agreement, Purchaser shall not assign, encumber or dispose of any interest in the Shares while the Shares are subject to the
Company’s Repurchase Option (as defined below). After any Shares have been released from such Repurchase Option, Purchaser shall not assign, encumber or dispose of any interest in such Shares except in compliance with the Stockholders
Agreement, the Plan and the Option Agreement. 

 (a)    Repurchase Option. 

(i)    In the event of the voluntary or involuntary termination of Purchaser’s Continuous Service Status with the
Company for any reason (including, without limitation, resignation, death or Disability), with or without Cause, the Company shall upon the date of such termination (the “Termination Date”) have an irrevocable, exclusive option (the
“Repurchase Option”) for a period of 3 months from such date to repurchase all or any portion of the Unvested Shares (as defined below) held by Purchaser as of the Termination Date at the original purchase price per Share (adjusted
for any stock splits, stock dividends and the like) specified in Section 1. As used herein, “Unvested Shares” means Shares that have not yet been released from the Repurchase Option. 

(ii)    Unless the Company notifies Purchaser within 3 months from the Termination Date that it does not intend to
exercise its Repurchase Option with respect to some or all of the Unvested Shares, the Repurchase Option shall be deemed automatically exercised by the Company as of the end of such 3-month period following
such termination, provided that the Company may notify Purchaser that it is exercising its Repurchase Option as of a date prior to the end of such 3-month period. Unless Purchaser is otherwise notified by the
Company pursuant to the preceding sentence that the Company does not intend to exercise its Repurchase Option as to some or all of the Unvested Shares to which it applies at the time of termination, execution of this Agreement by Purchaser
constitutes written notice to Purchaser of the Company’s intention to exercise its Repurchase Option with respect to all Unvested Shares to which such Repurchase Option applies. The Company, at its choice, may satisfy its payment obligation to
Purchaser with respect to exercise of the Repurchase Option by either (A) delivering a check to Purchaser in the amount of the purchase price for the Unvested Shares being repurchased, or (B) in the event Purchaser is indebted to the
Company, canceling an amount of such indebtedness equal to the purchase price for the Unvested Shares being repurchased, or (C) by a combination of (A) and (B) so that the combined payment and cancellation of indebtedness equals such
purchase price. In the event of any deemed automatic exercise of the Repurchase Option pursuant to this Section 3(a)(ii) in which Purchaser is indebted to the Company, such indebtedness equal to the purchase price of the Unvested Shares being
repurchased shall be deemed automatically canceled as of the end of such 3-month period following termination of Purchaser’s employment or consulting relationship unless the Company otherwise satisfies
its payment obligations. As a result of any repurchase of Unvested Shares pursuant to this Section 3(a), the Company shall become the legal and beneficial owner of the Unvested Shares being repurchased and shall have all rights and interest
therein or related thereto, and the Company shall have the right to transfer to its own name the number of Unvested Shares being repurchased by the Company, without further action by Purchaser. 

(iii)    One hundred percent (100%) of the Shares shall initially be subject to the Repurchase Option. The Unvested
Shares shall be released from the Repurchase Option in accordance with the Vesting Schedule set forth in the Notice of Stock Option Grant until all Shares are released from the Repurchase Option; provided, however, that such scheduled releases from
the Repurchase Option shall immediately cease as of the Termination Date. Fractional shares shall be rounded to the nearest whole share. 

 (b)    Restrictions Binding on Transferees. All
transferees of Shares or any interest therein will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of
the Option Agreement, including, without limitation, Section 7 of the Option Agreement and, insofar as applicable, the Repurchase Option. In the event the Repurchase Option is deemed exercised by the Company pursuant to Section 3(a)(ii)
hereof, the Company may deem any transferee to have transferred the Shares or interest to Purchaser prior to their purchase by the Company, and payment of the purchase price by the Company to such transferee shall be deemed to satisfy
Purchaser’s obligation to pay such transferee for such Shares or interest, and also to satisfy the Company’s obligation to pay Purchaser for such Shares or interest. Any sale or transfer of the Shares shall be void unless the provisions of
this Agreement are satisfied. 
 (c)    Lock-Up Agreement.
The lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms Purchaser’s obligations set forth
therein. 
 4.    Escrow of Unvested Shares. For purposes of facilitating the enforcement of the
provisions of Section 3(a) above, Purchaser agrees, immediately upon receipt of the stock certificate or, in the case of uncertificated securities, notice of issuance, for the Shares subject to the Repurchase Option, to deliver any such stock
certificate(s), as well as a Stock Power in the form attached to this Agreement as Attachment A executed by Purchaser and by Purchaser’s spouse (if required for transfer), in blank, to the Secretary of the Company, or
the Secretary’s designee, to hold such Shares (and such stock certificate(s), if any) and Stock Power in escrow and to take all such actions and to effectuate all such transfers and/or releases as are required in accordance with the terms of
this Agreement. Purchaser hereby acknowledges that the Secretary of the Company, or the Secretary’s designee, is so appointed as the escrow holder with the foregoing authorities as a material inducement to make this Agreement and that said
appointment is coupled with an interest and is accordingly irrevocable. Purchaser agrees that said escrow holder shall not be liable to any party hereof (or to any other party). The escrow holder may rely upon any letter, notice or other document
executed by any signature purported to be genuine and may resign at any time. Purchaser agrees that if the Secretary of the Company, or the Secretary’s designee, resigns as escrow holder for any or no reason, the Board shall have the power to
appoint a successor to serve as escrow holder pursuant to the terms of this Agreement. 
 5.    Investment and
Taxation Representations. In connection with the purchase of the Shares, Purchaser represents to the Company the following: 

(a)    Purchaser is aware of the Company’s business affairs and financial condition and has acquired sufficient
information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment for Purchaser’s own account only and not with a view to, or for resale in connection with,
any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any present intention to transfer the Shares to any other person or entity. 

(b)    Purchaser understands that the Shares have not been registered under the Securities Act by reason of a specific
exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

 (c)    Purchaser further acknowledges and understands that the securities
must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the
securities. 
 (d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act,
which, in substance, permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a
non-public offering subject to the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares
pursuant to Rule 144, which rule requires, among other things, that the Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain
specified time periods, and under certain circumstances, that resales of securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 5(d), Purchaser acknowledges and agrees to the
restrictions set forth in Section 5(e) below. 
 (e)    Purchaser further understands that in the event all of the
applicable requirements of Rule 144 are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not
exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a
substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

(f)    Purchaser understands that Purchaser may suffer adverse tax consequences as a result of Purchaser’s purchase
or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that Purchaser is not relying on the Company for any tax
advice. 
 6.    Voting Provisions. As condition precedent to entering into this Agreement,
Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to the terms of the Stockholders Agreement, including the
restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

7.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such legends as may
be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

 (b)    Stop-Transfer Notices. Purchaser agrees that, in
order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make
appropriate notations to the same effect in its own records. 
 (c)    Refusal to Transfer. The
Company shall not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to
vote or pay dividends to any purchaser or other transferee to whom such Shares shall have been so transferred. 

8.    No Employment Rights. Nothing in this Agreement shall affect in any manner whatsoever the right
or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting relationship, for any reason, with or without cause. 

9.    Section 83(b) Election. To the extent Purchase is or may
become subject to taxation in the United States, this Section 9 shall apply. 
 (a)    Purchaser understands that
Section 83(a) of the Internal Revenue Code of 1986, as amended (the “Code”), taxes as ordinary income for a Nonstatutory Stock Option and as alternative minimum taxable income for an Incentive Stock Option the difference
between the amount paid for the Shares and the Fair Market Value of the Shares as of the date any restrictions on the Shares lapse. In this context, “restriction” means the right of the Company to buy back the Shares pursuant to the
Repurchase Option set forth in Section 3(a) of this Agreement. Purchaser understands that Purchaser may elect to be taxed at the time the Shares are purchased, rather than when and as the Repurchase Option expires, by filing an election under
Section 83(b) (an “83(b) Election”) of the Code with the Internal Revenue Service within 30 days from the date of purchase. Even if the Fair Market Value of the Shares at the time of the execution of this Agreement equals the
amount paid for the Shares, the election must be made to avoid income and alternative minimum tax treatment under Section 83(a) in the future. Purchaser understands that failure to file such an election in a timely manner may result in adverse
tax consequences for Purchaser. Purchaser further understands that an additional copy of such election form should be filed with his or her federal income tax return for the calendar year in which the date of this Agreement falls. Purchaser
acknowledges that the foregoing is only a summary of the effect of United States federal income taxation with respect to purchase of the Shares hereunder, and does not purport to be complete, and is not intended or written to be used, and cannot be
used, for the purposes of avoiding taxpayer penalties. Purchaser further acknowledges that the Company has directed Purchaser to seek independent advice regarding the applicable provisions of the Code, the income tax laws of any municipality, state
or foreign country in which Purchaser may reside, and the tax consequences of Purchaser’s death, and Purchaser has consulted, and has been fully advised by, Purchaser’s own tax advisor regarding such tax laws and tax consequences or has
knowingly chosen not to consult such a tax advisor. Purchaser further acknowledges that neither the Company nor any subsidiary or representative of the Company has made any warranty or representation to Purchaser with respect to the tax consequences
of Purchaser’s purchase of the Shares or of the making or failure to make an 83(b) Election. PURCHASER (AND NOT THE COMPANY, ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR 

 
APPROPRIATELY FILING SUCH FORM WITH THE IRS, EVEN IF PURCHASER REQUESTS THE COMPANY, ITS AGENTS OR ANY OTHER PERSON MAKE THIS FILING ON PURCHASER’S BEHALF. 

(b)    Purchaser agrees that he or she will execute and deliver to the Company with this executed Agreement a copy of the
Acknowledgment and Statement of Decision Regarding Section 83(b) Election (the “Acknowledgment”) attached hereto as Attachment B. Purchaser further agrees that he or she will execute and submit with
the Acknowledgment a copy of the 83(b) Election attached hereto as Attachment C (for tax purposes in connection with the early exercise of an option) if Purchaser has indicated in the Acknowledgment his or her decision to
make such an election. 
 10.    Waiver of Statutory Information Rights. Purchaser acknowledges and
understands that, but for the waiver made herein, Purchaser would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the Company’s stock ledger, a
list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the General Corporation Law of Delaware (any and
all such rights, and any and all such other rights of Purchaser as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of the Company to the general
public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Purchaser hereby unconditionally and irrevocably waives the Inspection Rights,
whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign,
transfer, or cause to be commenced any claim, action, cause of action, or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Purchaser in Purchaser’s capacity as a stockholder
and shall not affect any rights of a director, in his or her capacity as such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Purchaser under any written agreement with the Company. 

11.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them relating to the
subject matter hereof. 

 (c)    Amendments and Waivers. No modification of or
amendment to this Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement shall
constitute a waiver of that provision as to that or any other instance. 
 (d)    Successors and
Assigns. Except as otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under
this Agreement, except with the prior written consent of the Company. 
 (e)    Notices. Any
notice, demand or request required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited in the
U.S. mail as certified or registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is specified on
the signature page, at the most recent address set forth in the Company’s books and records. 

(f)    Severability. If one or more provisions of this Agreement are held to be unenforceable under
applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this
Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms. 

(g)    Construction. This Agreement is the result of negotiations between and has been reviewed by
each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one of the parties hereto.

 (h)    Counterparts. This Agreement may be executed in any number of which when so executed and
delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company under the

 
statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any
qualification or registration under the Securities Act or otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the
imposition of excise taxes on the Company. 

 The parties have executed this Early Exercise Notice and Restricted Stock Purchase Agreement as
of the date first set forth above. 
  

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	
                     

		 	(Signature)
	Name:	 	
                     

	Title:	 	
                     

  

			
	Address:	 	
                     

		
		 	
                     

	
	PURCHASER:
	
	
                     

	(Signature)
		
	Address:	 	
                     

		
		 	
                     

		
	Email:	 	
                     

 I,
                                        , spouse
of                      (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

 ATTACHMENT A 

STOCK POWER 
 FOR
VALUE RECEIVED, the undersigned (“Holder”), hereby sells, assigns and transfers unto
                                         
                    (“Transferee”)                  shares
of the Common Stock of Twist Bioscience Corporation, a Delaware corporation (the “Company”), standing in Holder’s name on the Company’s books as Certificate No.
CS-                     whether held in certificated or uncertificated form, and does hereby irrevocably
constitute and appoint                      to transfer said stock on the books of the Company with full
power of substitution in the premises. 
  

							
	Dated:                                    
                         	 		 		 	HOLDER:
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Holder (if applicable)

 This Stock Power may only be used as authorized by the Early Exercise Notice and Restricted Stock Purchase
Agreement between the Holder and the Company, dated                      and the exhibits thereto. 

Instructions: Please do not fill in any blanks other than the signature line. The purpose of this assignment is to enable the
Company to exercise its repurchase option set forth in the Agreement without requiring additional signatures on the part of Holder. 

 IF YOU WISH TO MAKE A SECTION 83(B) 

ELECTION, THE FILING OF SUCH ELECTION 

IS YOUR RESPONSIBILITY. 
 THE FORM
FOR MAKING THIS SECTION 83(B) 
 ELECTION IS ATTACHED TO THIS 

AGREEMENT. 
 YOU MUST FILE THIS
FORM WITHIN 30 DAYS 
 OF PURCHASING THE SHARES. 

YOU (AND NOT THE COMPANY, ANY OF ITS AGENTS OR ANY OTHER PERSON) SHALL BE SOLELY RESPONSIBLE FOR FILING SUCH FORM WITH THE IRS, EVEN IF YOU
REQUEST 
 THE COMPANY, ITS AGENTS OR ANY OTHER 

PERSON TO MAKE THIS FILING ON YOUR 

BEHALF AND EVEN IF THE COMPANY, ANY 

OF ITS AGENTS OR ANY OTHER PERSON HAS 

PREVIOUSLY MADE THIS FILING ON YOUR 

BEHALF. 
 The election should be filed by mailing
a signed election form by certified mail, return receipt requested to the IRS Service Center where you file your tax returns. See www.irs.gov. 

 ATTACHMENT B 

ACKNOWLEDGMENT AND STATEMENT OF DECISION 

REGARDING SECTION 83(b) ELECTION 

The undersigned has entered into a stock purchase agreement with Twist Bioscience Corporation, a Delaware corporation (the
“Company”), pursuant to which the undersigned is purchasing                  shares of Common Stock of the Company (the “Shares”). In
connection with the purchase of the Shares, the undersigned hereby represents as follows: 
 1.    The undersigned has
carefully reviewed the stock purchase agreement pursuant to which the undersigned is purchasing the Shares. 
 2.    The
undersigned either [check and complete as applicable]: 
 (a)             has
consulted, and has been fully advised by, the undersigned’s own tax advisor,                     , whose business address is
                    , regarding the federal, state and local tax consequences of purchasing the Shares, and particularly regarding the advisability
of making elections pursuant to Section 83(b) of the Internal Revenue Code of 1986, as amended (the “Code”) and pursuant to the corresponding provisions, if any, of applicable state law; or 

(b)             has knowingly chosen not to consult such a tax advisor. 

3.    The undersigned hereby states that the undersigned has decided [check as applicable]: 

 

					
	(c)	 		  	to make an election pursuant to Section 83(b) of the Code, and is submitting to the Company, together with the undersigned’s executed stock purchase agreement, an executed form entitled “Election Under
Section 83(b) of the Internal Revenue Code of 1986;” or
			
	(d)	 	        	  	not to make an election pursuant to Section 83(b) of the Code.

 4.    Neither the Company nor any subsidiary or representative of the Company has
made any warranty or representation to the undersigned with respect to the tax consequences of the undersigned’s purchase of the Shares or of the making or failure to make an election pursuant to Section 83(b) of the Code or the
corresponding provisions, if any, of applicable state law. 
  

							
	Dated:
                                         
                   	 		 		 	PURCHASER:
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Purchaser (if applicable)

 ATTACHMENT C 

ELECTION UNDER SECTION 83(B) 

OF THE INTERNAL REVENUE CODE OF 1986 

The undersigned taxpayer hereby elects, pursuant to Section 83(b) of the Internal Revenue Code, to include in taxpayer’s gross
income or alternative minimum taxable income, as applicable, for the current taxable year, the amount of any income that may be taxable to taxpayer in connection with taxpayer’s receipt of the property described below: 

 

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

NAME OF TAXPAYER:
                     
 NAME OF
SPOUSE:                      

ADDRESS:
                                 

IDENTIFICATION NO. OF TAXPAYER:
                     

IDENTIFICATION NO. OF SPOUSE:
                     
 TAXABLE
YEAR:                      
  

	2.	The property with respect to which the election is made is described as follows: 

                 shares of the Common Stock of Twist
Bioscience Corporation, a Delaware corporation (the “Company”). 
  

	3.	The date on which the property was transferred is:                      

 

	4.	The property is subject to the following restrictions: 

 Repurchase option at cost in favor of
the Company upon termination of taxpayer’s employment or consulting relationship. 
  

	5.	The fair market value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms will never lapse, of such property is:
$        . 

  

	6.	The amount (if any) paid for such property: $        . 

 The undersigned has submitted a copy of this statement to the person for whom the services were performed in
connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the services in connection with the transfer of said property. 

The undersigned understands that the foregoing election may not be revoked except with the consent of the Commissioner. 

 

							
	Dated:
                                         
                                       	 		 		 	PURCHASER:
				
		 		 		 	  

		 		 		 	(Signature)
				
		 		 		 	  

		 		 		 	Spouse of Purchaser (if applicable)

 EXHIBIT A 

TWIST BIOSCIENCE CORPORATION 

2013 STOCK PLAN 

EXERCISE AGREEMENT 

This Exercise Agreement (this “Agreement”) is made as of
                    , by and between Twist Bioscience Corporation, a Delaware corporation (the “Company”), and
                     (“Purchaser”). To the extent any capitalized terms used in this Agreement are not defined, they shall have the
meaning ascribed to them in the Company’s 2013 Stock Plan and its Israeli Addendum (the “Plan”) and the Option Agreement (as defined below). 

1.    Exercise of Option. Subject to the terms and conditions hereof, Purchaser hereby elects to
exercise his or her option to purchase                  shares of the Common Stock (the “Shares”) of the Company under and pursuant to the Plan, the
Notice of Stock Option Grant and the Stock Option Agreement granted                      (the “Option Agreement”). The purchase
price for the Shares shall be $0.00001 per Share, for a total purchase price of $        . 

2.    Time and Place of Exercise. The purchase and sale of the Shares under this Agreement shall
occur at the principal office of the Company simultaneously with the execution and delivery of this Agreement, the payment of the aggregate exercise price by any method permitted in Section 4 of the Option Agreement, and the satisfaction of any
applicable tax, withholding, required deductions or other payments, all in accordance with the provisions of Section 3(b) of the Option Agreement. The Company shall issue the Shares to Purchaser by entering such Shares in Purchaser’s name
as of such date in the books and records of the Company or, if applicable, a duly authorized transfer agent of the Company, against payment of the exercise price therefor by Purchaser. With respect to 102 Trustee Award, the Shares issued upon
exercise of such 102 Trustee Award shall be issued to and in the name of the Trustee on behalf of Optionee, and shall be held by the Trustee in trust on behalf of Optionee. If applicable, the Company will deliver to Purchaser a certificate
representing the Shares as soon as practicable following such date. 
 3.    Limitations on Transfer.
In addition to any other limitation on transfer created by Applicable Laws, the Plan and the Option Agreement, Purchaser shall not assign, encumber or dispose of any interest in the Shares except in compliance with the Stockholders Agreement,
the Plan and the Option Agreement. 
 (a)    Restrictions Binding on Transferees. All transferees
of Shares or any interest therein will receive and hold such Shares or interest subject to the provisions of this Agreement, the Plan, the Stockholders Agreement and/or the Registration Rights Agreement, as applicable, and the terms of the Option
Agreement, including, without limitation, Section 7 of the Option Agreement. Any sale or transfer of the Shares shall be void unless the provisions of this Agreement are satisfied. 

 (b)    Lock-Up
Agreement. The lock-up provisions set forth in Section 7 of the Option Agreement shall apply to the Shares issued upon exercise of the Option hereunder and Purchaser reaffirms
Purchaser’s obligations set forth therein. 
 4.    Investment and Taxation Representations.
In connection with the purchase of the Shares, Purchaser represents to the Company the following: 

(a)    Purchaser is aware of the Company’s business affairs and financial condition and has acquired
sufficient information about the Company to reach an informed and knowledgeable decision to acquire the Shares. Purchaser is purchasing the Shares for investment for Purchaser’s own account only and not with a view to, or for resale in
connection with, any “distribution” thereof within the meaning of the Securities Act or under any applicable provision of state law. Purchaser does not have any present intention to transfer the Shares to any other person or entity. 

(b)    Purchaser understands that the Shares have not been registered under the Securities Act by reason of a specific
exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Purchaser’s investment intent as expressed herein. 

(c)    Purchaser further acknowledges and understands that the securities must be held indefinitely unless they are
subsequently registered under the Securities Act or an exemption from such registration is available. Purchaser further acknowledges and understands that the Company is under no obligation to register the securities. 

(d)    Purchaser is familiar with the provisions of Rule 144, promulgated under the Securities Act, which, in substance,
permits limited public resale of “restricted securities” acquired, directly or indirectly, from the issuer of the securities (or from an affiliate of such issuer), in a non-public offering subject to
the satisfaction of certain conditions. Purchaser understands that the Company provides no assurances as to whether he or she will be able to resell any or all of the Shares pursuant to Rule 144, which rule requires, among other things, that the
Company be subject to the reporting requirements of the Exchange Act, that resales of securities take place only after the holder of the Shares has held the Shares for certain specified time periods, and under certain circumstances, that resales of
securities be limited in volume and take place only pursuant to brokered transactions. Notwithstanding this Section 4(d), Purchaser acknowledges and agrees to the restrictions set forth in Section 4(e) below. 

(e)    Purchaser further understands that in the event all of the applicable requirements of Rule 144 are
not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption will be required; and that, notwithstanding the fact that Rule 144 is not exclusive, the Staff of the Securities and Exchange
Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rule 144 will have a substantial burden of proof in establishing that an exemption
from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. 

 (f)    Purchaser understands that Purchaser may suffer adverse tax
consequences as a result of Purchaser’s purchase or disposition of the Shares. Purchaser represents that Purchaser has consulted any tax consultants Purchaser deems advisable in connection with the purchase or disposition of the Shares and that
Purchaser is not relying on the Company for any tax advice. 
 5.    Voting Provisions. As
condition precedent to entering into this Agreement, Purchaser shall become a party to the Stockholders Agreement as an “Other Stockholder” by executing an the joinder agreement attached thereto and agreeing to be bound by and subject to
the terms of the Stockholders Agreement, including the restrictions on transfer contained therein, and to vote the Shares in the capacity of an “Other Stockholder” as defined in the Stockholders Agreement. 

6.    Restrictive Legends and Stop-Transfer Orders. 

(a)    Legends. Any certificate or certificates representing the Shares shall bear such
legends as may be required by the Stockholders Agreement, the Plan or the Registration Rights Agreement, as applicable, as well as any legends required by the Company or applicable state and federal corporate and securities laws. 

(b)    Stop-Transfer Notices. Purchaser agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in
its own records. 
 (c)    Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any
purchaser or other transferee to whom such Shares shall have been so transferred. 
 7.    No Employment
Rights. Nothing in this Agreement shall affect in any manner whatsoever the right or power of the Company, or a parent, subsidiary or affiliate of the Company, to terminate Purchaser’s employment or consulting
relationship, for any reason, with or without cause. 
 8.    Waiver of Statutory Information Rights.
Optionee acknowledges and understands that, but for the waiver made herein, Optionee would be entitled, upon written demand under oath stating the purpose thereof, to inspect for any proper purpose, and to make copies and extracts from, the
Company’s stock ledger, a list of its stockholders, and its other books and records, and the books and records of subsidiaries of the Company, if any, under the circumstances and in the manner provided in Section 220 of the Delaware
General Corporation Law (any and all such rights, and any and all such other rights of Optionee as may be provided for in Section 220, the “Inspection Rights”). In light of the foregoing, until the first sale of Common Stock of
the Company to the general public pursuant to a registration statement filed with and declared effective by the Securities and Exchange Commission under the Securities Act of 1933, as amended, Optionee hereby unconditionally and irrevocably waives
the Inspection Rights, whether such Inspection Rights would be exercised or pursued directly or indirectly pursuant to Section 220 or 

 
otherwise, and covenants and agrees never to directly or indirectly commence, voluntarily aid in any way, prosecute, assign, transfer, or cause to be commenced any claim, action, cause of action,
or other proceeding to pursue or exercise the Inspection Rights. The foregoing waiver applies to the Inspection Rights of Optionee in Optionee’s capacity as a stockholder and shall not affect any rights of a director, in his or her capacity as
such, under Section 220. The foregoing waiver shall not apply to any contractual inspection rights of Optionee under any written agreement with the Company. 

9.    Miscellaneous. 

(a)    Governing Law. The validity, interpretation, construction and performance of this Agreement,
and all acts and transactions pursuant hereto and the rights and obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the state of
Delaware, without giving effect to principles of conflicts of law. For purposes of litigating any dispute that may arise directly or indirectly from this Agreement, the parties hereby submit and consent to the exclusive jurisdiction of the
state of Delaware and agree that any such litigation shall be conducted only in the courts of Delaware or the federal courts of the United States located in Delaware and no other courts. 

(b)    Entire Agreement. This Agreement, together with the Option Agreement, the Notice and the Plan,
sets forth the entire agreement and understanding of the parties relating to the subject matter herein and supersedes all prior or contemporaneous discussions, understandings and agreements, whether oral or written, between them
relating to the subject matter hereof. 
 (c)    Amendments and Waivers. No modification of or
amendment to this Agreement, nor any waiver of any rights under this Agreement, shall be effective unless in writing signed by the parties to this Agreement. No delay or failure to require performance of any provision of this Agreement
shall constitute a waiver of that provision as to that or any other instance. 
 (d)    Successors and
Assigns. Except as otherwise provided in this Agreement, this Agreement, and the rights and obligations of the parties hereunder, will be binding upon and inure to the benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives. The Company may assign any of its rights and obligations under this Agreement. No other party to this Agreement may assign, whether voluntarily or by operation of law, any of its rights and obligations under
this Agreement, except with the prior written consent of the Company. 
 (e)    Notices. Any
notice, demand or request required or permitted to be given under this Agreement shall be in writing and shall be deemed sufficient when delivered personally or by overnight courier or sent by email, or 48 hours after being deposited
in the U.S. mail as certified or registered mail with postage prepaid, addressed to the party to be notified at such party’s address as set forth on the signature page, as subsequently modified by written notice, or if no address is
specified on the signature page, at the most recent address set forth in the Company’s books and records. 

 (f)    Severability. If one or more provisions of this
Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then
(i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its
terms. 
 (g)    Construction. This Agreement is the result of negotiations between and has been
reviewed by each of the parties hereto and their respective counsel, if any; accordingly, this Agreement shall be deemed to be the product of all of the parties hereto, and no ambiguity shall be construed in favor of or against any one
of the parties hereto. 
 (h)    Counterparts. This Agreement may be executed in any number of
which when so executed and delivered shall be deemed an original, and all of which together shall constitute one and the same agreement. 

(i)    Electronic Delivery. The Company may, in its sole discretion, decide to deliver any documents
related to this Agreement by electronic means. Purchaser hereby consents to receive such documents by electronic delivery and agrees to participate through an on-line or electronic system established and
maintained by the Company or a third party designated by the Company. 
 (j)    Compliance with Law.
If at any the Company or its counsel shall be of the opinion that any sale or delivery of Shares pursuant to this Agreement is or may in the circumstances be unlawful, or result in the imposition of excise taxes on the Company
under the statutes, rules or regulations of any applicable jurisdiction, the Company shall have no obligation to make such sale or delivery, or to make any application or to effect or to maintain any qualification or registration under the
Securities Act or otherwise with respect to Shares, and the right to purchase Shares shall be suspended until, in the opinion of said counsel, such sale or delivery shall be lawful and will not result in the imposition of excise taxes on the
Company. 

 The parties have executed this Exercise Agreement as of the date first set forth above. 

 

			
	THE COMPANY:
	
	TWIST BIOSCIENCE CORPORATION
		
	By:	 	  

		 	(Signature)
	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		
		 	  

	
	PURCHASER:
	
	  

	(Signature)	 	

 
			
		
	Address:	 	  

		
		 	  

		
	Email:	 	  

 I,
                                , spouse of
                     (“Purchaser”), have read and hereby approve the foregoing Agreement. In consideration of the Company’s
granting my spouse the right to purchase the Shares as set forth in the Agreement, I hereby agree to be bound irrevocably by the Agreement and further agree that any community property or other such interest that I may have in the Shares shall
hereby be similarly bound by the Agreement. I hereby appoint my spouse as my attorney-in-fact with respect to any amendment or exercise of any rights under the
Agreement. 
  

	
	  

	Spouse of Purchaser (if applicable)

 EXHIBIT C 

TWIST BIOSCIENCE CORPORATION. 

(the “Company”) 

Irrevocable Proxy and power of attorney 

Unless otherwise defined, capitalized terms used herein shall have the meaning ascribed to them under the Company’s Stock Plan and are incorporated
herein by reference. 
 I, the undersigned, hereby irrevocably appoints the Company, which shall designate such person or persons as
determined by the Administrator (and in the absence of such determination, the CEO or Chairman of the Board of Directors of the Company, ex officio), with full power of substitution, as my proxy and attorney-in-fact to: (i) cause any number of shares, of any class, of the Company owned by me or by the Trustee for my benefit, under the Plan or any other share incentive or option plan of the Company,
and any other shares or securities issued or distributed in respect thereto or in substitution or exchange thereof, at any time and from time to time, and as may be adjusted (collectively, the “Shares”), to be counted as present at
any and all Shareholders Meetings (as defined below); (ii) represent me and to vote in my name at any and all Shareholders Meetings in respect of the Shares; (iii) sign and execute on my behalf any written resolutions or consents in lieu of a
Shareholder Meeting or any other consent, in respect of the Shares; (iv) exercise or fail to exercise, in the proxyholder’s sole and absolute discretion, any rights or obligations attached to any and all Shares, and sign on my behalf any
document or instrument relating to such rights or obligations, including, without limitation, shareholders agreements, documents concerning rights of bring along, tag along, first refusal, preemptive rights,
co-sale rights, information rights, registration rights, lock-up/market stand-off and any other rights or obligations, if any,
whether included in the incorporation documents of the Company or any other document or instrument as shall be from time to time (which exercise may impose on the undersigned monetary liability in connection with a Merger/Sale); and (v) agree
to the offer to effect a Merger/Sale on the terms approved by the Board (and the Shares held by me or for my benefit shall be included in the shares of the Company approving the terms of such Merger/Sale for the purpose of satisfying any required
majority), sell all of the Shares held by me or for my benefit, in accordance with the instructions then issued by the Board, whose determination shall be final, and sign on my behalf any document or instrument relating thereto, including, without
limitation, share transfer documents, as are required to affect a compulsory sale of Shares in connection with a Merger/Sale pursuant to the Plan; (vi) receive all notices and communications with respect to the above, including, without
limitation, notices of any Shareholders Meeting (including any adjournment or postponement thereof) or any written resolution or consent in lieu thereof. “Shareholders Meetings” shall mean any meeting of the shareholders of the
Company, however called, whether an extraordinary or annual meeting and whether of the share capital as one class or of any class thereof, and including any adjournment or postponement thereof), or any act or consent of shareholders of the Company
(whether of the share capital as one class or of any class thereof) under the Company’s Articles of Association or otherwise. 
 In any
Shareholders Meeting or written consent in lieu thereof, the Shares shall be voted by the proxy holder, unless directed otherwise by the Board, in the same proportion as the result 

 
of the vote at the Shareholders Meeting in respect of which the Shares are being voted, and in any act or consent of shareholders under the Company’s Articles of Association or otherwise,
such Shares shall be cast by the proxy holder, unless directed otherwise by the Board, in the same proportion as the result of the shareholders’ act or consent. 

As long as this proxy and power of attorney is in effect, any and all voting rights I may have with respect to the Shares shall be exercised
exclusively by this proxy and power of attorney. The undersigned hereby revokes any proxy(ies) and power of attorney heretofore given in respect of the Shares to any person(s) and agrees not to give any other proxies or and power of attorney in
derogation or preventing the undersigned from complying with its obligations hereof, until such time as this proxy is no longer in full force and effect. The undersigned acknowledges and agrees that this proxy shall be irrevocable and is a special
power of attorney coupled with an interest sufficient in law to support an irrevocable power and shall survive the bankruptcy, death, adjudication of incompetence or the like of undersigned. This proxy and power of attorney shall survive the
transfer of Shares, until duly replaced by a similar power and power of attorney executed by the transferee. The Company is an intended third party beneficiary of this proxy and power of attorney. Any person holding or exercising such voting proxies
is doing so solely in his/her capacity as the proxy holder and not individually. This proxy shall terminate and be of no further force and effect immediately after the listing for trading on a stock exchange or market or trading system of shares of
the Company or of the Successor Corporation (as such term is defined in the Plan). 

 IN WITNESS WHEREOF, the undersigned has executed this IRREVOCABLE PROXY as of the date written
below. 
  

			
	Signature:	 	
                     
                    

	Printed Name:	 	
                     
                    

	ID number:	 	
                     
                    

	Date:EX-10.4

 Exhibit 10.4 

TWIST BIOSCIENCE CORPORATION 

EXECUTIVE INCENTIVE BONUS PLAN 
  

	1.	 PURPOSE 

The purpose of the Twist Bioscience Corporation Executive Incentive Bonus Plan (as amended from time to time, the
“Plan”) is to motivate and reward eligible employees for their contributions toward the achievement of certain Performance Goals (as defined below) by Twist Bioscience Corporation (together with its subsidiaries, the
“Company”). 
  

	2.	 DEFINITIONS 

The following definitions shall be applicable throughout the Plan: 

(a) “Award” means the amount of cash incentive payable under the Plan to a Participant with respect to a
Performance Period. 
 (b) “Board” means the Board of Directors of the Company, as constituted from time to
time. 
 (c) “Code” means the Internal Revenue Code of 1986, as amended. Reference to a specific section of
the Code or regulation thereunder shall include such section or regulation, any valid regulation promulgated under such section, and any comparable provision of any future legislation or regulation amending, supplementing or superseding such section
or regulation. 
 (d) “Committee” means the Compensation Committee of the Board or another Committee
designated by the Board. As of the Effective Date, the Plan shall be administered by the Compensation Committee of the Board. 
 (e)
“Effective Date” means the day immediately prior to the date on which the Company’s Registration Statement is declared effective by the Securities and Exchange Commission. 

(f) “Participant” means any officer or employee of the Company who is designated as a Participant by the
Committee. 
 (g) “Performance Goal” means a formula or standard determined by the Committee with respect to
each Performance Period based on one or more of the following criteria and any adjustment(s) thereto established by the Committee: (1) sales or non-sales revenue; (2) return on revenues;
(3) operating income; (4) income or earnings including operating income; (5) income or earnings before or after taxes, interest, depreciation and/or amortization; (6) income or earnings from continuing operations; (7) net
income; (8) pre-tax income or after-tax income; (9) net income excluding amortization of intangible assets, depreciation and impairment of goodwill and
intangible assets and/or excluding charges attributable to the adoption of new accounting pronouncements; (10) raising of financing or fundraising; (11) project financing; (12) revenue backlog; (13) gross margin;
(14) operating margin or profit margin; (15) capital expenditures, cost targets, reductions and savings and expense management; (16) return on assets (gross or net), return on investment, return on capital, return on invested capital,
or return on shareholder equity; 

 
(17) cash flow, free cash flow, cash flow return on investment (discounted or otherwise), net cash provided by operations, or cash flow in excess of cost of capital; (18) performance
warranty and/or guarantee claims; (19) stock price or total stockholder return; (20) earnings or book value per share (basic or diluted); (21) economic value created; (22) pre-tax profit or after-tax profit; (23) strategic business criteria, consisting of one or more objectives based on meeting specified market penetration or market share, completion of strategic agreements such as licenses, joint
ventures, acquisitions, and the like, geographic business expansion, objective customer satisfaction or information technology goals, intellectual property asset metrics; (24) objective goals relating to divestitures, joint ventures, mergers,
acquisitions and similar transactions; (25) objective goals relating to staff management, results from staff attitude and/or opinion surveys, staff satisfaction scores, staff safety, staff accident and/or injury rates, compliance, headcount,
performance management, completion of critical staff training initiatives; (26) objective goals relating to projects, including project completion, timing and/or achievement of milestones, project budget, technical progress against work plans;
and (27) enterprise resource planning. Awards issued to Participants may take into account other factors (including subjective factors). Performance Goals may differ from Participant to Participant, Performance Period to Performance Period and
from Award to Award. Any criteria used may be measured, as applicable, (i) in absolute terms, (ii) in relative terms (including, but not limited to, any increase (or decrease) over the passage of time and/or any measurement against other
companies or financial or business or stock index metrics particular to the Company), (iii) on a per share and/or share per capita basis, (iv) against the performance of the Company as a whole or against any affiliate(s), or a particular
segment(s), a business unit(s) or a product(s) of the Company or individual project company, (v) on a pre-tax or after-tax basis, and/or (vi) using an actual
foreign exchange rate or on a foreign exchange neutral basis. 
 (h) “Performance Period” means the
Company’s fiscal year, multiple fiscal years or any other period longer or shorter than one fiscal year, as determined by the Committee, in its sole discretion. The Committee may establish different Performance Periods for different
Participants, and the Committee may establish concurrent or overlapping Performance Periods. 
 (i) “Reliance
Period” means the reliance period under the applicable rule set forth in Treasury Regulation Section 1.162-27(f)(2). 
  

	3.	 ADMINISTRATION 

(a) The Plan shall be administered by the Committee, which shall have the discretionary authority to interpret the provisions of the
Plan, including all decisions on eligibility to participate, the establishment of Performance Goals, the amount of Awards payable under the Plan, and the payment of Awards. The Committee shall also have the discretionary authority to establish rules
under the Plan so long as such rules do not explicitly conflict with the terms of the Plan and any such rules shall constitute part of the Plan. The decisions of the Committee shall be final and binding on all parties making claims under the Plan.
The Committee, in its sole discretion and on such terms and conditions as it may provide, may delegate all or part of its authority and powers under the Plan to one or more directors and/or officers of the Company. 

  
 2 

	4.	 ELIGIBILITY 

Officers and other key employees of the Company designated by the Committee to participate in the Plan shall be eligible to participate in this
Plan, provided the Committee has not, in its sole discretion, withdrawn such designation and he or she meets the following conditions: 

(a) is a full-time regular employee of the Company as of the last day of the applicable Performance Period; and 

(b) is not subject to disciplinary action, is in good standing with the Company and is not subject to a performance improvement plan.

  

	5.	 AMOUNT OF AWARDS 

(a) With respect to each Participant, the Committee will establish one or more Performance Periods, an individual Participant incentive
target (which may be, but is not required to be, based on the Participant’s base salary) for each Performance Period and the Performance Goal(s) to be met during such Performance Period(s). 

(b) Except as otherwise required by applicable law or as determined by the Committee, base salary shall not include salary paid during
any paid leave of absence or any variable forms of compensation including, but not limited to, overtime, on-call pay, lead premiums, shift differentials, bonuses, incentive compensation, commissions, stock
options, restricted stock units, restricted stock, stock appreciation rights, or expense allowances or reimbursements. Nothing in the Plan, or arising as a result of a Participant’s participation in the Plan, shall prevent the Company from
changing a Participant’s base salary at any time based on such factors as the Company shall in its discretion determine appropriate. 

(c) Awards may be pro-rated on any basis determined appropriate in the Committee’s sole
discretion, including, but not limited to, in connection with transfers to new positions or new locations, new hires, Participants on a leave of absence for all or any portion of a Performance Period, or Participants working less than full-time. The
Committee reserves the right, in its sole discretion, to increase, reduce or eliminate the amount of an Award otherwise payable to a Participant with respect to any Performance Period. 

(d) In addition, the amount of the aggregate value of any Awards payable under the Plan to covered employees (as determined under Code
Section 162(m)) in reliance upon the transition rule promulgated under Treasury Regulation Section 1.162-27(f) may not exceed $15,000,000 during the entire Reliance Period. 

 

	6.	 PAYMENT OF AWARDS 

(a) Unless otherwise determined by the Committee, a Participant must be actively employed and in good standing with the Company on the
date the Award is paid. The Committee may make exceptions to this requirement in the case of retirement, death or disability, an unqualified leave of absence or under other circumstances, as determined by the Committee in its sole discretion. 

  
 3 

 (b) Any distribution made under the Plan shall be made in cash and occur within a
reasonable period of time after the end of the Performance Period in which the Participant has earned the Award. Notwithstanding the foregoing, in order to comply with the short-term deferral exception under Code Section 409A, if the Committee
waives the requirement that a Participant must be employed on the date the Award is to be paid, payout shall occur no later than the 15th day of the third month following the later of (i) the end of the Company’s taxable year in which such
Award is earned or (ii) the end of the calendar year in which such Award is earned, or shall otherwise be structured to comply with, or be exempt from, Code Section 409A. 

 

	7.	 GENERAL 

(a) TAX WITHHOLDING. The Company shall have the right to deduct from all Awards any federal, state or local income and/or payroll taxes,
and any other deductions, required to be withheld with respect to such payments. The Company also may withhold such amounts from any other amount payable by the Company or any affiliate to the Participant. 

(b) CLAIM TO AWARDS AND EMPLOYMENT RIGHTS. Nothing in the Plan shall confer on any Participant the right to continued employment with
the Company or any of its affiliates, or affect in any way the right of the Company or any affiliate to terminate the Participant’s employment at any time, and for any reason, or change the Participant’s responsibilities. Awards represent
unfunded and unsecured obligations of the Company and a holder of any right hereunder in respect of any Award shall have no rights other than those of a general unsecured creditor to the Company. 

(c) BENEFICIARIES. To the extent the Committee permits beneficiary designations, any payment of Awards under the Plan to a deceased
Participant shall be paid to the beneficiary duly designated by the Participant in accordance with the Company’s practices. If no such beneficiary has been designated or survives the Participant, payment shall be made to the Participant’s
legal representative, legal beneficiary or estate, as applicable. A beneficiary designation may be changed or revoked by a Participant at any time, provided the change or revocation is filed with the Committee prior to the Participant’s death.

 (d) NONTRANSFERABILITY. A person’s rights and interests under the Plan, including any Award previously made to such person or
any amounts payable under the Plan, may not be sold, assigned, pledged, transferred or otherwise alienated or hypothecated except, in the event of a Participant’s death, to a designated beneficiary as provided in the Plan, or in the absence of
such designation, by will or the laws of descent and distribution. 
 (e) SUCCESSOR. All obligations of the Company under the Plan,
with respect to Awards granted hereunder, shall be binding on any successor to the Company, whether the existence of such successor is the result of a direct or indirect purchase, merger, consolidation, or otherwise, of all or substantially all of
the business or assets of the Company. 
 (f) INDEMNIFICATION. Each person who is or shall have been a member of the Committee and
each employee of the Company or an affiliate who is delegated a duty under the Plan shall be indemnified and held harmless by the Company from and against any loss, cost, 

  
 4 

 
liability or expense that may be imposed upon or reasonably incurred by him or her in connection with or resulting from any claim, action, suit or proceeding to which he or she may be a party or
in which he or she may be involved by reason of any action or failure to act under the Plan and against and from any and all amounts paid by him or her in satisfaction of judgment in any such action, suit or proceeding against him or her, provided
such loss, cost, liability or expense is not attributable to such person’s willful misconduct. Any person seeking indemnification under this provision shall give the Company prompt notice of any claim and shall give the Company an opportunity,
at its own expense, to handle and defend the same before the person undertakes to handle and defend such claim on his or her own behalf. The foregoing right of indemnification shall not be exclusive of any other rights of indemnification to which
such persons may be entitled, including under the Company’s Articles of Incorporation or Bylaws, as a matter of law, or otherwise, or any power that the Company may have to indemnify them or hold them harmless. 

(g) EXPENSES. The expenses of administering the Plan shall be borne by the Company. 

(h) TITLES AND HEADINGS. The titles and headings of the sections in the Plan are for convenience of reference only, and in the event of
any conflict, the text of the Plan, rather than such titles or headings, shall control. 
 (i) INTENT. It is the intent of this Plan
that all payments hereunder be exempt from the requirements of Code Section 409A so that none of the payments to be provided under this Plan will be subject to the adverse tax penalties imposed under Section 409A, and any ambiguities or
ambiguous terms herein will be interpreted to be so exempt. The Company and each Participant will work together in good faith to consider amendments to the Plan or revisions to the Plan with respect to the payment of any Awards under the Plan, which
are necessary or appropriate to avoid imposition of any additional tax or income recognition prior to the actual payment to the Participant under Code Section 409A. In no event will the Company reimburse a Participant for any taxes or other
penalties that may be imposed on the Participant as a result of Code Section 409A. 
 (j) GOVERNING LAW. The validity,
construction, and effect of the Plan, any rules and regulations relating to the Plan, and any Award shall be determined in accordance with the laws of the State of California (without giving effect to principles of conflicts of laws thereof) and
applicable federal law. 
 (k) AMENDMENTS AND TERMINATION. The Committee may terminate the Plan at any time, provided such termination
shall not affect the payment of any Awards accrued under the Plan prior to the date of the termination. The Committee may, at any time, or from time to time, amend or suspend and, if suspended, reinstate, the Plan in whole or in part; provided,
however, that any amendment of the Plan shall be subject to the approval of the Company’s shareholders to the extent required to comply with applicable laws, regulations or rules. 

  
 5

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