Longitude funds adjust Rapid Micro Biosystems (RPID) stake in Form 4

Rhea-AI Filing Summary

Rapid Micro Biosystems, Inc. (RPID) reported insider activity involving investment funds managed by Longitude Capital. Longitude Venture Partners II, L.P. exercised warrants for 629,032 shares of Class A common stock at $0.05 per share on a cashless basis, with 7,739 shares withheld to cover the exercise price.

After these transactions, Longitude Venture Partners II, L.P. held 4,029,245 Class A shares indirectly. Separate from this, Longitude Prime Fund, L.P. sold 46,000, 27,500 and 27,500 Class A shares on January 30, 2026, February 2, 2026 and February 3, 2026 at prices between $4.24 and $4.54 per share, leaving it with 49,000 shares owned indirectly.

The filing explains that Longitude Capital Partners II, LLC and Longitude Prime Partners, LLC are general partners of the respective funds, and individuals Patrick G. Enright and Juliet Tammenoms Bakker are managing members, all disclaiming 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

OMB APPROVAL

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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)
01/23/2026

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	01/23/2026		X(1)		629,032	A	$0.05	4,036,984	I	Held by Longitude Venture Partners II, L.P.(2)
Class A Common Stock	01/23/2026		S(1)		7,739	D	$4.064	4,029,245	I	Held by Longitude Venture Partners II, L.P.(2)
Class A Common Stock	01/30/2026		S		46,000	D	$4.5435	104,000	I	Held by Longitude Prime Fund, L.P.(3)
Class A Common Stock	02/02/2026		S		27,500	D	$4.246	76,500	I	Held by Longitude Prime Fund, L.P.(3)
Class A Common Stock	02/03/2026		S		27,500	D	$4.2415	49,000	I	Held by Longitude Prime Fund, L.P.(3)

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
Class A Common Stock	$0.05	01/23/2026		X			500,000	(4)	07/24/2027	Class A Common Stock	500,000	$0	0	I	Held by Longitude Venture Partners II, L.P.(2)
Class A Common Stock	$0.05	01/23/2026		X			129,032	(4)	01/17/2028	Class A Common Stock	129,032	$0	0	I	Held by Longitude Venture Partners II, L.P.(2)

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^*

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. Longitude Venture Partners II, L.P. ("LVPII") exercised warrants to purchase an aggregate of 629,032 shares of the Issuer's Class A common stock for $0.05 per share and paid the exercise price on a cashless basis, resulting in the Issuer withholding 7,739 shares of the Issuer's shares of Class A common stock subject to the warrant to pay the exercise price.

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.

3. 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.

4. The warrant is immediately exercisable.

	/s/ Longitude Capital Partners II, LLC, By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/03/2026
	/s/ Longitude Venture Partners II, L.P., By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/03/2026
	/s/ Longitude Prime Partners, LLC, By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/03/2026
	/s/ Longitude Prime Fund, L.P., By: /s/ Cristiana Blauth Oliveira, Authorized Signatory	02/03/2026
	/s/ Cristiana Blauth Oliveira, as attorney-in-fact for Patrick G. Enright	02/03/2026
	/s/ Cristiana Blauth Oliveira, as attorney-in-fact for Juliet Tammenoms Bakker	02/03/2026
	** Signature of Reporting Person	Date
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FAQ

What insider transactions were reported in the Rapid Micro Biosystems (RPID) Form 4?

The Form 4 reports warrant exercises and share sales by Longitude-affiliated funds. Longitude Venture Partners II, L.P. exercised 629,032 warrants, while Longitude Prime Fund, L.P. sold several blocks of Class A shares and reduced its indirect holdings to 49,000 shares.

Who actually holds the Rapid Micro Biosystems (RPID) shares in this Form 4?

The shares are held by investment funds, not individuals. Longitude Venture Partners II, L.P. and Longitude Prime Fund, L.P. directly hold the securities, while their general partners and managing members may be deemed to share voting power but disclaim beneficial ownership beyond pecuniary interests.

How many Rapid Micro Biosystems shares did Longitude Venture Partners II, L.P. acquire and at what price?

Longitude Venture Partners II, L.P. exercised warrants for 629,032 Class A shares at an exercise price of $0.05 per share. The exercise was cashless, so 7,739 shares were withheld by the issuer to satisfy the aggregate exercise price obligation under the warrants.

What sales of Rapid Micro Biosystems (RPID) stock did Longitude Prime Fund, L.P. report?

Longitude Prime Fund, L.P. reported three open-market sales of Class A common stock. It sold 46,000 shares at $4.5435, then 27,500 shares at $4.246, and another 27,500 shares at $4.2415, leaving 49,000 shares indirectly owned after these transactions.

How did the cashless warrant exercise affect Rapid Micro Biosystems share counts in this filing?

A cashless exercise by Longitude Venture Partners II, L.P. converted warrants into 629,032 Class A shares. To cover the $0.05 per share exercise cost, the issuer withheld 7,739 shares, so the fund received the remaining shares while no cash changed hands for the exercise price.

Do Patrick G. Enright and Juliet Tammenoms Bakker personally own the Rapid Micro Biosystems shares in this Form 4?

They are managing members of entities with potential voting and dispositive power over fund-held shares, but the filing states they disclaim beneficial ownership, except to the extent of any pecuniary interest they may have in the Longitude investment vehicles that hold the securities.