Rapid Micro CEO exercises options for 1,402 shares

Rapid Micro Biosystems, Inc. reports that President and CEO Robert G. Spignesi Jr. exercised a stock option for 1,402 shares of Class A Common Stock on July 22, 2026 at an exercise price of $0.75 per share.

Rhea-AI Filing Summary

Rapid Micro Biosystems, Inc. reports that President and CEO Robert G. Spignesi Jr. exercised a stock option for 1,402 shares of Class A Common Stock on July 22, 2026 at an exercise price of $0.75 per share. The underlying option, which was fully vested and exercisable and scheduled to expire on August 11, 2026, was fully exercised and no longer remains outstanding. Following this transaction, Spignesi directly holds 1,191,973 shares of Class A Common Stock, with no shares sold in this filing.

Insider Trade Summary

1,402 shares exercised/converted

Exercise 2 txns

Insider Spignesi Robert G. Jr.

Role PRESIDENT AND CEO

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F1	1,402	$0.00	$0.00
Exercise	Class A Common Stock	1,402	$0.75	$1K

Holdings After Transaction: Stock Option (Right to Buy) — 0 contracts (Direct); Class A Common Stock — 1,191,973 shares (Direct)

Footnotes (1)

1. F1. The option is fully vested and exercisable.

Key Figures

Shares acquired via option exercise: 1,402 shares Exercise price: $0.75 per share Shares owned after transaction: 1,191,973 shares +2 more

5 metrics

Shares acquired via option exercise 1,402 shares Class A Common Stock acquired on July 22, 2026 through option exercise

Exercise price $0.75 per share Strike price of stock option exercised for 1,402 shares

Shares owned after transaction 1,191,973 shares Direct Class A Common Stock holdings of CEO following the exercise

Option expiration date August 11, 2026 Expiration date of fully exercised stock option grant

Derivative shares exercised 1,402 shares Stock Option (Right to Buy) converted into Class A Common Stock

Key Terms

Stock Option (Right to Buy), Class A Common Stock, Exercise or conversion of derivative security

3 terms

Stock Option (Right to Buy) financial

"security_title: Stock Option (Right to Buy)"

Class A Common Stock financial

"underlying_security_title: Class A Common Stock"

Class A common stock is a category of a company’s shares that carries a specific set of ownership rights—most commonly defined voting power and claims on dividends—set out in the company’s charter. For investors it matters because the class determines how much influence you have over corporate decisions, the share’s likely dividend and trading behavior, and how it compares in value to other share classes, like choosing a particular seat with different privileges at the company’s decision-making table.

Exercise or conversion of derivative security financial

"transaction_code_description: Exercise or conversion of derivative security"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did RPID CEO Robert G. Spignesi Jr. report?

Robert G. Spignesi Jr. exercised a stock option for 1,402 shares of Rapid Micro Biosystems Class A Common Stock at an exercise price of $0.75 per share on July 22, 2026, increasing his directly held common shares.

How many Rapid Micro Biosystems (RPID) shares does the CEO own after this Form 4?

After the reported transaction, Robert G. Spignesi Jr. directly owns 1,191,973 shares of Rapid Micro Biosystems Class A Common Stock. This figure reflects the addition of 1,402 shares acquired through the option exercise reported on July 22, 2026.

What was the exercise price of the RPID stock options in this Form 4?

The stock option was exercised at an exercise price of $0.75 per share for 1,402 shares of Class A Common Stock. The derivative entry shows a zero price because it represents the option itself, which converted into common shares at this stated strike price.

Did the RPID CEO sell any shares in the July 22, 2026 transaction?

No shares were sold in this filing; the CEO exercised options to acquire 1,402 shares of Class A Common Stock. The derivative position was disposed of mechanically as part of the option exercise, with common shares added to his direct holdings.

What happened to the Rapid Micro Biosystems (RPID) option that expired August 11, 2026?

The reported option, fully vested and exercisable, covered 1,402 shares at $0.75 per share and had an expiration date of August 11, 2026. It was fully exercised on July 22, 2026, leaving 0 shares remaining under that option grant.

Is the RPID CEO’s transaction on this Form 4 part of a 10b5-1 trading plan?

The filing’s Rule 10b5-1 checkbox is not marked as a plan transaction. The option exercise is reported without any accompanying footnote indicating that it was carried out under a pre-arranged 10b5-1 trading plan.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 07/24/2026 - 06:30 PM Accepted by SEC EDGAR 07/24/2026 - 06:29 PM Learn about SEC filing dates

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

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Spignesi Robert G. Jr.

(Last) (First) (Middle)

C/O RAPID MICRO BIOSYSTEMS, INC.

25 HARTWELL AVENUE

(Street)

LEXINGTON MASSACHUSETTS 02421

(City) (State) (Zip)

UNITED STATES

(Country)

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
X	Officer (give title below)		Other (specify below)
	PRESIDENT AND CEO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
07/22/2026

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

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

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

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	07/22/2026		M		1,402	A	$0.75	1,191,973	D

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
Stock Option (Right to Buy)	$0.75	07/22/2026		M			1,402	(1)	08/11/2026	Class A Common Stock	1,402	$0	0	D

Explanation of Responses:

1. The option is fully vested and exercisable.

Remarks:

	/s/ Sean M. Wirtjes, Attorney-in-Fact for Robert G. Spignesi, Jr.	07/24/2026
	** Signature of Reporting Person	Date
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.
* Form 4: SEC 1474 (03-26)