Inese Lowenstein - 21 May 2026 Form 4 Insider Report for RAPID MICRO BIOSYSTEMS, INC. (RPID)

Reporting relationship: Director
Issuer ticker: RPID
Reported as of: 21 May 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 26 May 2026, 19:26:00 UTC
Prior SEC filing: 27 May 2025
Next SEC filing: 02 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Robert Spignesi, Attorney-in-Fact for Inese Lowenstein

Key filing fact

Inese Lowenstein filed Form 4 for RAPID MICRO BIOSYSTEMS, INC. (RPID) on 26 May 2026.

Key facts

This page summarizes Inese Lowenstein's Form 4 filing for RAPID MICRO BIOSYSTEMS, INC. (RPID).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 26 May 2026, 19:26.

Change

Previous filing in this sequence was filed on 27 May 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001900476 Primary reporting owner

LOWENSTEIN INESE

Relationship: Director
Address: C/O RAPID MICRO BIOSYSTEMS, INC., 25 HARTWELL AVENUE, LEXINGTON
Signature: /s/ Robert Spignesi, Attorney-in-Fact for Inese Lowenstein
Signature date: 26 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

RPID transaction

Class A Common Stock

Award

Transaction value
Shares: +19,300
Change %: +50%
Price: $0.000000^*
Shares after: 57,900
Date: 21 May 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

RPID transaction Derivative

Stock Option (Right to Buy)

Award

Transaction value
Shares: +38,700
Change %
Price: $0.000000^*
Shares after: 38,700
Date: 21 May 2026
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 38,700
Exercise price: $2.07
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Grant of restricted stock units ("RSUs") that vests in full on the earlier of (i) the first anniversary of the Grant Date, or (ii) the day immediately prior to the date of the next annual meeting of the stockholders of the Company provided that the Reporting Person remains in continuous service on such vesting date.

Footnote F2

The option shall vest and become exercisable in full on the earlier of (i) the first anniversary of the Grant Date, or (ii) the day immediately prior to the date of the next annual meeting of the stockholders of the Company provided that the Reporting Person remains in continuous service on such vesting date.