Exhibit 10.4


 


SERA PROGNOSTICS, INC.


 


EMPLOYEE STOCK PURCHASE PLAN


 


The following constitute the
provisions of the 2021 Employee Stock Purchase Plan (the “Plan”) of Sera Prognostics, Inc. (the “Company”).


 


1.             Purpose. The purpose of the Plan is to provide Employees of the Company and its Designated Subsidiaries with an opportunity
to purchase Common Stock of the Company. It is the intention of the Company to have the Plan qualify as an “Employee Stock Purchase
Plan” under Section 423 of the Code. The provisions of the Plan shall, accordingly, be construed so as to extend and limit participation
in a manner consistent with the requirements of that section of the Code.


 


2.             Definitions.


 


(a)               
“Board” shall mean the Board of Directors of the Company, or a committee of the Board of Directors named by
the Board to administer the Plan.


 


(b)              
“Code” shall mean the Internal Revenue Code of 1986, as amended, including any successor statute, regulation
and guidance thereto.


 


(c)               
“Common Stock” shall mean the class A common stock, $0.0001 par value per share, of the Company.


 


(d)              
“Company” shall mean Sera Prognostics, Inc., a Delaware corporation.


 


(e)             
“Compensation” shall mean the regular rate of salary or wages received by the Employee from the Company or a
Designated Subsidiary that is taxable income for federal income tax purposes or applicable tax law, including payments for overtime and
shift premium, but excluding incentive compensation, incentive payments, bonuses, commissions, relocation, expense reimbursements, tuition
or other reimbursements or compensation received from the Company or a Designated Subsidiary.


 


(f)               
“Continuous Status as an Employee” shall mean the absence of any interruption or termination of service as an
Employee. Continuous Status as an Employee shall not be considered interrupted in the case of a leave of absence agreed to in writing
by the Company, provided that such leave is for a period of not more than ninety (90) days or reemployment upon the expiration of such
leave is guaranteed by contract or statute.


 


(g)               
“Contributions” shall mean all amounts credited to the account of a participant pursuant to the Plan.


 


(h)             
“Designated Subsidiaries” shall mean the Subsidiaries which have been designated by the Board from time to time
in its sole discretion as eligible to participate in the Plan.


 






     


     


    

 


(i)                 
“Employee” shall mean any person who is employed by the Company or one of its Designated Subsidiaries for tax
purposes and who is customarily employed for at least twenty (20) hours per week and more than five (5) months in a calendar year by the
Company or one of its Designated Subsidiaries.


 


(j)                
“Exercise Date” shall mean the last business day of each Offering Period of the Plan.


 


(k)               
“Exercise Price” shall mean with respect to an Offering Period, an amount equal to 85% of the fair market value
(as defined in Section 7(b)) of a share of Common Stock on the Offering Date or on the Exercise Date, whichever is lower.


 


(l)                 
“Offering Date” shall mean the first business day of each Offering Period of the Plan.


 


(m)            
“Offering Period” shall mean a period of six months as set forth in Section 4 of the Plan.


 


(n)              
“Plan” shall mean this Sera Prognostics, Inc. Employee Stock Purchase Plan.


 


(o)             
“Subsidiary” shall mean a corporation, domestic or foreign, of which not less than 50% of the voting shares
are held by the Company or a Subsidiary, whether or not such corporation now exists or is hereafter organized or acquired by the Company
or a Subsidiary.


 


3.                 
Eligibility.


 


(a)               
Any person who has been continuously employed as an Employee for three (3) months as of the Offering Date of a given Offering Period
shall be eligible to participate in such Offering Period under the Plan and further, subject to the requirements of Section 5(a) and the
limitations imposed by Section 423(b) of the Code. All Employees granted options under the Plan with respect to any Offering Period will
have the same rights and privileges except for any differences that may be permitted pursuant to Section 423.


 


(b)              
Any provisions of the Plan to the contrary notwithstanding, no Employee shall be granted an option under the Plan (i) if,
immediately after the grant, such Employee (or any other person whose stock would be attributed to such Employee pursuant to Section 424(d)
of the Code) would own stock and/or hold outstanding options to purchase stock possessing five percent (5%) or more of the total combined
voting power or value of all classes of stock of the Company or of any Subsidiary of the Company or (ii) which permits his or her
rights to purchase stock under all employee stock purchase plans (described in Section 423 of the Code) of the Company and its Subsidiaries
to accrue at a rate which exceeds $25,000 of fair market value of such stock as defined in Section 7(b) (determined at the time such option
is granted) for each calendar year in which such option is outstanding at any time. In addition, the maximum number of shares of Common
Stock that may be purchased by any participant during an Offering Period shall equal the lesser of (i) 5,000 shares of Common Stock or
(ii) $25,000 divided by the fair market value of the Common Stock on the first trading day of such Offering Period, which price shall
be adjusted if the price per share is adjusted pursuant to Section 18. Any option granted under the Plan shall be deemed to be modified
to the extent necessary to satisfy this Section 3(b).


 






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4.            Offering Periods. The Plan shall be implemented by a series of Offering Periods, with a new Offering Period commencing on
June 1 and December 1 of each year or the first business day thereafter (or at such other time or times as may be determined by the Board).


 


5.            
Participation.


 


(a)               
An eligible Employee may become a participant in the Plan by completing an Enrollment Form provided by the Company and filing it
with the Company or its designee at least fifteen (15) days prior to the applicable Offering Date, unless a later time for filing the
Enrollment Form is set by the Board for all eligible Employees with respect to a given Offering Period. The Enrollment Form and its submission
may be electronic as directed by the Company. The Enrollment Form shall set forth the percentage of the participant’s Compensation
(which shall be not less than one percent (1%) and not more than fifteen percent (15%) to be paid as Contributions pursuant to the Plan.


 


(b)               
Payroll deductions shall commence with the first payroll following the Offering Date, unless a later time is set by the Board with
respect to a given Offering Period, and shall end on the last payroll paid on or prior to the Exercise Date of the Offering Period to
which the Enrollment Form is applicable, unless sooner terminated as provided in Section 10.


 


6.            Method of Payment of Contributions.


 


(a)               
Each participant shall elect to have payroll deductions made on each payroll during the Offering Period in an amount not less than
one percent (1%) and not more than fifteen percent (15%) of such participant’s Compensation on each such payroll (or such other
percentage as the Board may establish from time to time before an Offering Date). All payroll deductions made by a participant shall be
credited to his or her account under the Plan. A participant may not make any additional payments into such account.


 


A participant may discontinue
his or her participation in the Plan as provided in Section 10, or, on one occasion only during the Offering Period, may decrease, but
may not increase, the rate of his or her Contributions during the Offering Period by completing and filing with the Company a new Enrollment
Form authorizing a change in the deduction rate. The change in rate shall be effective as of the beginning of the next payroll period
following the date of filing of the new Enrollment Form, if the Enrollment Form is submitted at least fifteen (15) days prior to such
date, and, if not, as of the beginning of the next succeeding payroll period.


 


(b)              
Notwithstanding the foregoing, to the extent necessary to comply with Section 423(b)(8) of the Code and Section 3(b), a participant’s
payroll deductions may be decreased to 0% at such time during any Offering Period which is scheduled to end during the current calendar
year that the aggregate of all payroll deductions accumulated with respect to such Offering Period and any other Offering Period ending
within the same calendar year equals $21,250. Payroll deductions shall recommence at the rate provided in such participant’s Enrollment
Form at the beginning of the first Offering Period which is scheduled to end in the following calendar year, unless terminated by the
participant as provided in Section 10.


 






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7.            Grant of Option.


 


(a)               
On the Offering Date of each Offering Period, each eligible Employee participating in such Offering Period shall be granted an
option to purchase on the Exercise Date of such Offering Period a number of shares of the Common Stock determined by dividing such Employee’s
Contributions accumulated prior to such Exercise Date and retained in the participant’s account as of the Exercise Date by the applicable
Exercise Price; provided however, that such purchase shall be subject to the limitations set forth in Sections 3(b) and 12. The fair market
value of a share of the Common Stock shall be determined as provided in Section 7(b).


 


(b)              
The fair market value of the Common Stock on a given date shall be (i) if the Common Stock is listed on a national securities exchange
or traded in the over-the-counter market and sales prices are regularly reported for the Common Stock, the closing or last sale price
of the Common Stock for such date (or, in the event that the Common Stock is not traded on such date, on the immediately preceding trading
date), on the composite tape or other comparable reporting system; or (ii) if the Common Stock is not listed on a national securities
exchange and such price is not regularly reported, the mean between the bid and asked prices per share of the Common Stock at the close
of trading in the over-the-counter market.


 


8.            
Exercise of Option. Unless a participant withdraws from the Plan as provided in Section 10, his or her option for the purchase
of shares will be exercised automatically on the Exercise Date of the Offering Period, and the maximum number of full shares subject to
the option will be purchased for him or her at the applicable Exercise Price with the accumulated Contributions in his or her account.
If a fractional number of shares results, then such number shall be rounded down to the next whole number and any unapplied cash shall
be carried forward to the next Exercise Date, unless the participant requests a cash payment. The shares purchased upon exercise of an
option hereunder shall be deemed to be transferred to the participant on the Exercise Date. During a participant’s lifetime, a participant’s
option to purchase shares hereunder is exercisable only by him or her.


 


9.            Delivery. Upon the written request of a participant, certificates representing the shares purchased upon exercise of an
option will be issued as promptly as practicable after the Exercise Date of each Offering Period to participants who wish to hold their
shares in certificate form, except that the Board may determine that such shares shall be held for each participant’s benefit by
a broker designated by the Board. Any payroll deductions accumulated in a participant’s account which are not sufficient to purchase
a full Share shall be retained in the participant’s account for the subsequent Offering Period, subject to earlier withdrawal by
the participant as provided in Section 10 below. Any other amounts left over in a participant’s account after an Exercise Date shall
be returned to the participant.


 






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10.           Withdrawal; Termination of Employment. A participant may withdraw all but not less than all the Contributions credited to
his or her account under the Plan at any time prior to the Exercise Date of the Offering Period by giving written notice to the Company
or its designee. All of the participant’s Contributions credited to his or her account will be paid to him or her promptly after
receipt of his or her notice of withdrawal and his or her option for the current period will be automatically terminated, and no further
Contributions for the purchase of shares will be made during the Offering Period.


 


(a)               
Upon termination of the participant’s Continuous Status as an Employee prior to the Exercise Date of the Offering Period
for any reason, including retirement or death, the Contributions credited to his or her account will be returned to him or her or, in
the case of his or her death, to the person or persons entitled thereto under Section 14, and his or her option will be automatically
terminated.


 


(b)              
In the event an Employee fails to remain in Continuous Status as an Employee for at least 20 hours per week during the Offering
Period in which the Employee is a participant, he or she will be deemed to have elected to withdraw from the Plan and the Contributions
credited to his or her account will be returned to him or her and his or her option terminated.


 


A participant’s withdrawal
from an Offering Period will not have any effect upon his or her eligibility to participate in a succeeding offering or in any similar
plan which may hereafter be adopted by the Company.


 


11.          
Interest. No interest shall accrue on the Contributions of a participant in the Plan.


 


12.           Stock.


 


(a)                The
maximum number of shares of Common Stock which shall be made available for sale under the Plan shall be 305,089
shares, subject to adjustment upon changes in capitalization of the Company as provided in Section 18. In addition to the foregoing,
subject to Section 18, on the first day of each calendar year beginning on and including January 1, 2022 and ending on and including
January 1, 2031, the number of shares of Common Stock available for sale under the Plan shall be increased by that number of shares
equal to the lesser of (a) one percent (1%) of the number of outstanding shares on the final day of the immediately preceding
calendar year and (b) such smaller number of shares as determined by the Board. If the total number of shares which would otherwise
be subject to options granted pursuant to Section 7(a) on the Offering Date of an Offering Period exceeds the number of shares then
available under the Plan (after deduction of all shares for which options have been exercised), the Company shall make a pro rata
allocation of the shares remaining available for option grants in as uniform a manner as shall be practicable and as it shall
determine to be equitable. Any amounts remaining in an Employee’s account not applied to the purchase of shares pursuant to
this Section 12 shall be refunded on or promptly after the Exercise Date. In such event, the Company shall give written notice of
such reduction of the number of shares subject to the option to each Employee affected thereby and shall similarly reduce the rate
of Contributions, if necessary.


 


(b)              
The participant will have no interest or voting right in shares covered by his or her option until such option has been exercised.


 






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13.          Administration. The Board shall supervise and administer the Plan and shall have full power to adopt, amend and rescind
any rules deemed desirable and appropriate for the administration of the Plan and not inconsistent with the Plan, to construe and interpret
the Plan, to correct any defect or supply any omission or reconcile any inconsistency or ambiguity in the Plan and to make all other determinations
necessary or advisable for the administration of the Plan, including without limitation, adopting subplans applicable to particular Designated
Subsidiaries or locations, which subplans may be designed to be outside the scope of Section 423 of the Code..


 


14.           Designation of Beneficiary. A participant may designate a beneficiary who is to receive any shares and cash, if any, from
the participant’s account under the Plan in the event of such participant’s death subsequent to the end of the Offering Period
but prior to delivery to him or her of such shares and cash. In addition, a participant may designate a beneficiary who is to receive
any cash from the participant’s account under the Plan in the event of such participant’s death prior to the Exercise Date
of the Offering Period. If a participant is married and the designated beneficiary is not the spouse, spousal consent shall be required
for such designation to be effective. Beneficiary designations shall be made either in writing or by electronic delivery as directed by
the Company.


 


(a)               
Such designation of beneficiary may be changed by the participant (and his or her spouse, if any) at any time by submission of
the required notice, which may be electronic. In the event of the death of a participant and in the absence of a beneficiary validly designated
under the Plan who is living at the time of such participant’s death, the Company shall deliver such shares and/or cash to the executor
or administrator of the estate of the participant, or if no such executor or administrator has been appointed (to the knowledge of the
Company), the Company, in its discretion, may deliver such shares and/or cash to the spouse or to any one or more dependents or relatives
of the participant, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate.


 


15.           Transferability. Neither Contributions credited to a participant’s account nor any rights with regard to the exercise
of an option or to receive shares under the Plan may be assigned, transferred, pledged or otherwise disposed of in any way (other than
by will, the laws of descent and distribution or as provided in Section 14) by the participant. Any such attempt at assignment, transfer,
pledge or other disposition shall be without effect, except that the Company may treat such act as an election to withdraw funds in accordance
with Section 10.


 






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16.           Use of Funds. All Contributions received or held by the Company under the Plan may be used by the Company for any corporate
purpose, and the Company shall not be obligated to segregate such Contributions.


 


17.           Reports. Individual accounts will be maintained for each participant in the Plan. Statements of account will be given to
participating Employees promptly following the Exercise Date, which statements will set forth the amounts of Contributions, the per share
purchase price, the number of shares purchased and the remaining cash balance, if any.


 


18.           Adjustments upon Changes in Capitalization. Subject to any required action by the stockholders of the Company, the number
of shares of Common Stock covered by unexercised options under the Plan and the number of shares of Common Stock which have been authorized
for issuance under the Plan but are not yet subject to options under Section 12(a) (collectively, the “Reserves”), the maximum
number of shares of Common Stock that may be purchased by a participant in an Offering Period set forth in Section 3(b) as well as the
price per share of Common Stock covered by each unexercised option under the Plan, shall be proportionately adjusted for any increase
or decrease in the number of issued shares of Common Stock resulting from a stock split, reverse stock split, stock dividend, combination
or reclassification of the Common Stock. Such adjustment shall be made by the Board, whose determination in that respect shall be final,
binding and conclusive.


 


In the event of the proposed
dissolution or liquidation of the Company, an Offering Period then in progress will terminate immediately prior to the consummation of
such proposed action, unless otherwise provided by the Board. In the event of a proposed sale of all or substantially all of the assets
of the Company, or the merger, consolidation or other capital reorganization of the Company with or into another corporation, each option
outstanding under the Plan shall be assumed or an equivalent option shall be substituted by such successor corporation or a parent or
subsidiary of such successor corporation, unless the Board determines, in the exercise of its sole discretion and in lieu of such assumption
or substitution, to shorten the Offering Period then in progress by setting a new Exercise Date (the “New Exercise Date”).
If the Board shortens the Offering Period then in progress in lieu of assumption or substitution in the event of a merger or sale of assets,
the Board shall notify each participant in writing, at least ten days prior to the New Exercise Date, that the Exercise Date for his or
her option has been changed to the New Exercise Date and that his or her option will be exercised automatically on the New Exercise Date,
unless prior to such date he or she has withdrawn from the Offering Period as provided in Section 10. For purposes of this section, an
option granted under the Plan shall be deemed to be assumed if, following the sale of assets, merger or other reorganization, the option
confers the right to purchase, for each share of Common Stock subject to the option immediately prior to the sale of assets, merger or
other reorganization, the consideration (whether stock, cash or other securities or property) received in the sale of assets, merger or
other reorganization by holders of Common Stock for each share of Common Stock held on the effective date of such transaction (and if
such holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding
shares of Common Stock); provided, however, that if such consideration received in such transaction was not solely common stock of the
successor corporation or its parent (as defined in Section 424(e) of the Code), the Board may, with the consent of the successor corporation,
provide for the consideration to be received upon exercise of the option to be solely common stock of the successor corporation or its
parent equal in fair market value to the per share consideration received by holders of Common Stock in the sale of assets, merger or
other reorganization.


 


The Board may, if it so determines
in the exercise of its sole discretion, also make provision for adjusting the Reserves, as well as the price per share of Common Stock
covered by each outstanding option, in the event that the Company effects one or more reorganizations, recapitalizations, rights offerings
or other increases or reductions of shares of its outstanding Common Stock, and in the event of the Company being consolidated with or
merged into any other corporation.


 






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19.          
Amendment or Termination.


 


(a)               
The Board may at any time terminate or amend the Plan. Except as provided in Section 18, no such termination may affect options
previously granted, nor may an amendment make any change in any option theretofore granted which adversely affects the rights of any participant
provided that an Offering Period may be terminated by the Board on an Exercise Date or by the Board’s setting a new Exercise Date
with respect to an Offering Period then in progress if the Board determines that termination of the Offering Period is in the best interests
of the Company and the stockholders or if continuation of the Offering Period would cause the Company to incur adverse accounting charges
in the generally-accepted accounting rules applicable to the Plan. In addition, to the extent necessary to comply with Section 423 of
the Code (or any successor rule or provision or any applicable law or regulation), the Company shall obtain stockholder approval in such
a manner and to such a degree as so required.


 


(b)              
Without stockholder consent and without regard to whether any participant rights may be considered to have been adversely affected,
the Board shall be entitled to change the Offering Periods, limit the frequency and/or number of changes in the amount withheld during
an Offering Period, establish the exchange ratio applicable to amounts withheld in a currency other than U.S. dollars, permit payroll
withholding in excess of the amount designated by a participant in order to adjust for delays or mistakes in the Company’s processing
of properly completed withholding elections, establish reasonable waiting and adjustment periods and/or accounting and crediting procedures
to ensure that amounts applied toward the purchase of Common Stock for each participant properly correspond with amounts withheld from
the participant’s Compensation, and establish such other limitations or procedures as the Board determines in its sole discretion
advisable that are consistent with the Plan.


 


20.           Notices. All notices or other communications by a participant to the Company under or in connection with the Plan shall
be deemed to have been duly given when received in the form specified by the Company at the location, or by the person, designated by
the Company for the receipt thereof.


 






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21.          
Conditions upon Issuance of Shares. Shares shall not be issued with respect to an option unless the exercise of such option
and the issuance and delivery of such shares pursuant thereto shall comply with all applicable provisions of law, domestic or foreign,
including, without limitation, the Securities Act of 1933, as amended, the Securities Exchange Act of 1934, as amended, the rules and
regulations promulgated thereunder, and the requirements of any stock exchange upon which the shares may then be listed, and shall be
further subject to the approval of counsel for the Company with respect to such compliance.


 


As a condition to the exercise
of an option, the Company may require the person exercising such option to represent and warrant at the time of any such exercise 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 required by any of the aforementioned applicable provisions of law.


 


22.          Information Regarding Disqualifying Dispositions. By electing to participate in the Plan, each participant agrees to provide
any information about any transfer of shares of Common Stock acquired under the Plan that occurs within two years after the first business
day of the Offering Period in which such shares were acquired as may be requested by the Company or any Subsidiaries in order to assist
it in complying with the tax laws.


 


23.           Right to Terminate Employment. Nothing in the Plan or in any agreement entered into pursuant to the Plan shall confer upon
any Employee the right to continue in the employment of the Company or any Subsidiary, or affect any right which the Company or any Subsidiary
may have to terminate the employment of such Employee.


 


24.           Rights as a Stockholder. Neither the granting of an option nor a deduction from payroll shall constitute an Employee the
owner of shares covered by an option. No Employee shall have any right as a stockholder unless and until an option has been exercised,
and the shares underlying the option have been registered in the Company’s share register.


 


25.          
Term of Plan. The Plan became effective upon its adoption by the Board on June 30, 2021 and shall continue in effect through
June 30, 2031, unless sooner terminated under Section 19.


 


26.           Applicable Law. This Plan shall be governed in accordance with the laws of the State of Delaware, applied without giving
effect to any conflict-of-law principles.


 






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