EX-4.2



 Exhibit 4.2 
 




 
 NUMBER 
ST 
SERES 
THERAPEUTICSTM 
Seres Therapeutics, Inc. 
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE 
SHARES 
SEE REVERSE FOR CERTAIN DEFINITIONS 
CUSIP 81750R 10 2 
This Certifies that 
SPECIMEN 
is the owner of 
FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK PAR VALUE $0.001 PER SHARE OF 
Seres
Therapeutics, Inc. 
transferable on the books of the Corporation in person or by duly authorized attorney upon surrender of this certificate properly endorsed.

This certificate is not valid unless countersigned and registered by the Transfer Agent and Registrar. WITNESS the facsimile signatures of the duly authorized
officers of the Corporation. 
CERTIFICATE OF STOCK 
DATED 
COUNTERSIGNED AND REGISTERED: 
AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC 
(Brooklyn, NY) 
TRANSFER AGENT AND REGISTRAR BY: 
AUTHORIZED SIGNATURE 
CHIEF FINANCIAL OFFICER AND TREASURER 
PRESIDENT AND CHIEF EXECUTIVE OFFICER 
SECURITY COLUMBIAN UNITED STATES BANKNOTE COMPANY 1960








 SERES THERAPEUTICS, INC. 

THE CORPORATION IS AUTHORIZED TO ISSUE TWO CLASSES OF STOCK, COMMON STOCK AND PREFERRED STOCK. THE COMPANY WILL FURNISH WITHOUT CHARGE TO EACH SHAREHOLDER WHO
SO REQUESTS, A SUMMARY OF THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL, OR OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OF THE COMPANY AND THE QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS OF SUCH PREFERENCES AND/OR
RIGHTS, AND THE VARIATIONS IN RIGHTS, PREFERENCES AND LIMITATIONS DETERMINED FOR EACH SERIES WHICH ARE FIXED BY THE CERTIFICATE OF INCORPORATION OF THE COMPANY AND THE AUTHORITY OF THE BOARD OF DIRECTORS TO DETERMINE VARIATIONS FOR FUTURE SERIES.
SUCH REQUEST MAY BE MADE TO THE OFFICE OF THE SECRETARY OF THE COMPANY OR TO THE TRANSFER AGENT. 
 The following abbreviations, when used
in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: 
  

																			
	TEN COM		—		as tenants in common				UNIF GIFT MIN ACT		—		  
		Custodian		  

	TEN ENT		—		as tenants by the entireties								(Cust)				(Minor)
	JT TEN		—		as joint tenants with right of survivorship and not as tenants in common								under Uniform Gifts to Minors
												Act		  
		
														(State)		

 Additional abbreviations may also be used though not in the above list. 

For value received,
                                         hereby
sells, assigns and transfers unto 
  

	
	PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE
	 
	 

  
  

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) 

 
  
  

 
  

			
	  
		shares
	represented by the within Certificate, and does hereby irrevocably constitute and appoint

  

			
	  
		, attorney
	to transfer the said shares on the books of the within named Corporation with full power of substitution in the premises.

  

			
	Dated		  


  

					
					  

			NOTICE:		THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.

  

	
	Signature(s) Guaranteed:
	
	  

	THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C.
RULE 17Ad-15.