Inese Lowenstein - 29 May 2026 Form 4 Insider Report for RAPID MICRO BIOSYSTEMS, INC. (RPID)

Reporting relationship: Director
Issuer ticker: RPID
Reported as of: 29 May 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 02 Jun 2026, 19:45:47 UTC
Prior SEC filing: 26 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Sean M. Wirtjes, Attorney-in-Fact for Inese Lowenstein

Key filing fact

Inese Lowenstein filed Form 4 for RAPID MICRO BIOSYSTEMS, INC. (RPID) on 02 Jun 2026.

Key facts

This page summarizes Inese Lowenstein's Form 4 filing for RAPID MICRO BIOSYSTEMS, INC. (RPID).
3 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 02 Jun 2026, 19:45.

Change

Previous filing in this sequence was filed on 26 May 2026.
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/ Sean M. Wirtjes, Attorney-in-Fact for Inese Lowenstein
Signature date: 02 Jun 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: +12,787
Change %: +22%
Price: $1.96^*
Shares after: 70,687
Date: 29 May 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

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

RPID transaction Derivative

Series A Warrant (right to buy)

Award

Transaction value
Shares: +12,787
Change %
Price: $0.000000^*
Shares after: 12,787
Date: 29 May 2026
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 12,787
Exercise price: $1.96
Footnotes: F1, F2

RPID transaction Derivative

Series B Warrant (right to buy)

Award

Transaction value
Shares: +12,787
Change %
Price: $0.000000^*
Shares after: 12,787
Date: 29 May 2026
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 12,787
Exercise price: $2.34
Footnotes: F1, 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

On May 29, 2026, the Reporting Person purchased, in a registered direct offering, 12,787 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each share of Issuer Class A Common Stock and accompanying Series A and Series B Warrant was $1.955. The issuance of such securities was approved by the Issuer's compensation committee of the board of directors in accordance with Rule 16(b)-3 of the Securities Exchange Act of 1934, as amended.

Footnote F2

The Series A and Series B Warrants cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 4.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.