Longitude entities (RPID) log 49,000-share sale and 4.0M-share holding

Rhea-AI Filing Summary

Rapid Micro Biosystems, Inc. insider entities reported a share sale and updated holdings. On February 4, 2026, Longitude Prime Fund, L.P. reported an indirect sale of 49,000 shares of Class A common stock at $3.8794 per share, leaving it with no reported shares afterward.

Separately, Longitude Venture Partners II, L.P. reported continued indirect beneficial ownership of 4,029,245 shares of Class A common stock. General partner entities and individuals associated with these funds may be deemed to share voting and dispositive power but expressly disclaim beneficial ownership beyond their pecuniary interests.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

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X

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Longitude Capital Partners II, LLC

(Last) (First) (Middle)

C/O LONGITUDE CAPITAL MANAGEMENT

2740 SAND HILL ROAD, 2ND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
RAPID MICRO BIOSYSTEMS, INC. [ RPID ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
02/04/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	02/04/2026		S		49,000	D	$3.8794	0	I	Held by Longitude Prime Fund, L.P.(1)
Class A Common Stock								4,029,245	I	Held by Longitude Venture Partners 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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person^*

Longitude Capital Partners II, LLC

(Last) (First) (Middle)

C/O LONGITUDE CAPITAL MANAGEMENT

2740 SAND HILL ROAD, 2ND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Longitude Venture Partners II, L.P.

(Last) (First) (Middle)

2740 SAND HILL ROAD, SECOND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Longitude Prime Partners, LLC

(Last) (First) (Middle)

2740 SAND HILL ROAD, SECOND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Longitude Prime Fund, L.P.

(Last) (First) (Middle)

2740 SAND HILL ROAD, SECOND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

ENRIGHT PATRICK G

(Last) (First) (Middle)

2740 SAND HILL ROAD, SECOND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Tammenoms Bakker Juliet

(Last) (First) (Middle)

2740 SAND HILL ROAD, SECOND FLOOR

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. The securities are held directly by Longitude Prime Fund, L.P. ("LPF"). Longitude Prime Partners, LLC ("LPP"), the general partner of LPF, may be deemed to have voting and dispositive power with respect to the shares held by LPF. Mr. Enright and Ms. Tammenoms Bakker are the managing members of LPP and may be deemed to have voting and dispositive power over the shares held by LPF. LPP and each of Mr. Enright and Ms. Tammenoms Bakker disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein.

2. The securities are held directly by LVPII. Longitude Capital Partners II, LLC, ("LCPII"), the general partner of LVPII, may be deemed to have voting and dispositive power with respect to the shares held by LVPII. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of LCPII and may be deemed to share voting and dispositive power over the shares held by LVPII. Each of LCPII, Mr. Enright and Ms. Tammenoms Bakker disclaim beneficial ownership of such securities and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

	/s/ Longitude Capital Partners II, LLC, By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/06/2026
	/s/ Longitude Venture Partners II, L.P., By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/06/2026
	/s/ Longitude Prime Partners, LLC, By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/06/2026
	/s/ Longitude Prime Fund, L.P., By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/06/2026
	/s/ Cristiana Blauth Oliveira, as attorney-in-fact for Patrick G. Enright	02/06/2026
	/s/ Cristiana Blauth Oliveira, as attorney-in-fact for Juliet Tammenoms Bakker	02/06/2026
	** Signature of Reporting Person	Date
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FAQ

What insider transaction did RPID report for Longitude Prime Fund on February 4, 2026?

Longitude Prime Fund, L.P. reported an indirect sale of 49,000 shares of Rapid Micro Biosystems Class A common stock at $3.8794 per share on February 4, 2026. Following this transaction, it reported holding 0 shares of the stock.

How many RPID shares does Longitude Venture Partners II, L.P. report owning after this Form 4?

Longitude Venture Partners II, L.P. reports indirect beneficial ownership of 4,029,245 shares of Rapid Micro Biosystems Class A common stock after the reported activity. These shares are held by the fund, with related entities potentially sharing voting and dispositive power as described in the filing footnotes.

Who is attributed with the 49,000-share sale of Rapid Micro Biosystems stock?

The 49,000-share sale of Rapid Micro Biosystems Class A common stock is attributed to Longitude Prime Fund, L.P., which directly holds the securities. Related entities and individuals may be deemed to have voting and dispositive power but disclaim beneficial ownership beyond their pecuniary interests.

What role do Longitude Prime Partners, LLC and its managing members play in the RPID holdings?

Longitude Prime Partners, LLC is the general partner of Longitude Prime Fund, L.P. and may be deemed to have voting and dispositive power over its Rapid Micro Biosystems shares. Its managing members, Patrick G. Enright and Juliet Tammenoms Bakker, also may share such power but disclaim beneficial ownership beyond pecuniary interests.

How is Longitude Capital Partners II, LLC related to the RPID shares held by LVPII?

Longitude Capital Partners II, LLC is the general partner of Longitude Venture Partners II, L.P. and may be deemed to have voting and dispositive power over LVPII’s 4,029,245 RPID shares. It, along with its managing members, disclaims beneficial ownership except to the extent of their pecuniary interests.

Do the individuals associated with the Longitude entities claim full beneficial ownership of the RPID shares?

No. The filing states that related entities and individuals, including Patrick G. Enright and Juliet Tammenoms Bakker, disclaim beneficial ownership of the Rapid Micro Biosystems shares, except to the extent of their respective pecuniary interests in the relevant funds and entities.