Sec Form 4 Filing - Kollender Richard S @ RAPID MICRO BIOSYSTEMS, INC. - 2021-07-19

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Kollender Richard S 2. Issuer Name and Ticker or Trading Symbol RAPID MICRO BIOSYSTEMS, INC. [ RPID] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O RAPID MICRO BIOSYSTEMS, INC., 1001 PAWTUCKET BOULEVARD WEST, SUITE 280 3. Date of Earliest Transaction (MM/DD/YY) 07/19/2021 (Street) LOWELL, MA01854 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Class A Common Stock 07/19/2021 C 1,315,084 A 1,373,193 I Held by Quaker Bioventures II, L.P. ( 2 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series A1 Preferred Stock ( 1 ) 07/19/2021 C 4,623,796 ( 1 ) ( 1 ) Class A Common Stock 924,759 ( 1 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Series B1 Preferred Stock ( 1 ) 07/19/2021 C 1,130,906 ( 1 ) ( 1 ) Class A Common Stock 226,180 ( 1 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Series C1 Preferred Stock ( 1 ) 07/19/2021 C 820,729 ( 1 ) ( 1 ) Class A Common Stock 164,145 ( 1 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Series A1 Warrant $ 0.01 07/19/2021 C( 3 ) 410,051 ( 3 ) 07/24/2027 Series A1 Preferred Stock 410,051 ( 3 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Common Stock Warrant $ 0.05 07/19/2021 C 82,010 ( 4 ) 07/24/2027 Class A Common Stock 82,010 ( 3 ) 82,010 I Held by Quaker Bioventures II, L.P. ( 2 ) Series B1 Warrant $ 0.01 07/19/2021 C( 3 ) 64,516 ( 4 ) 01/17/2028 Series B1 Preferred Stock 64,516 ( 3 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Common Stock Warrant $ 0.05 07/19/2021 C 12,903 ( 4 ) 01/17/2028 Class A Common Stock 12,903 ( 3 ) 12,903 I Held by Quaker Bioventures II, L.P. ( 2 ) Series B1 Warrant $ 0.01 07/19/2021 C( 3 ) 64,516 ( 4 ) 12/06/2027 Series B1 Preferred Stock 64,516 ( 3 ) 0 I Held by Quaker Bioventures II, L.P. ( 2 ) Common Stock Warrant $ 0.05 07/19/2021 C 12,903 ( 4 ) 12/06/2027 Class A Common Stock 12,903 ( 3 ) 12,903 I Held by Quaker Bioventures II, L.P. ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Kollender Richard S C/O RAPID MICRO BIOSYSTEMS, INC. 1001 PAWTUCKET BOULEVARD WEST, SUITE 280 LOWELL, MA01854 X Signatures /s/ Jonathan Paris, Attorney-in-Fact for Richard Kollender 07/20/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Series A1 Preferred Stock, the Series B1 Preferred Stock and the Series C1 Preferred Stock (collectively, the "Preferred Stock") are convertible at any time, at the holder's election and have no expiration date. Each share of Preferred Stock automatically converted into 0.20 shares of the Issuer's Class A Common Stock upon the closing of the Issuer's initial public offering. ( 2 )These shares are held directly by Quaker Bioventures II, L.P. The Reporting Person is a managing director of Quaker Bioventures Capital II, L.P., the parent of Quaker Bioventures II, L.P. and may be deemed to beneficially hold the shares. ( 3 )The Issuer's Preferred Stock warrants automatically converted into warrants to purchase Common Stock immediately prior to the closing of the Issuer's initial public offering without payment or further consideration. The transaction is listed solely for the purpose of reporting the change in the shares underlying the warrants. ( 4 )Immediately exercisable.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.