WIRTJES SEAN M 4

What Happened

• Sean M. Wirtjes, Chief Financial Officer of Rapid Micro Biosystems (RPID), disposed of 6,027 shares on 2026-02-09 at $3.78 per share, for a total of $22,798. The filing indicates this was an automatic sale to cover tax obligations arising from the vesting of restricted stock units (RSUs), so it is a routine tax-withholding sale rather than a discretionary market sell.

Key Details

• Transaction date: 2026-02-09
• Transaction type: Sale (S) — 6,027 shares sold at $3.78 each
• Proceeds: $22,798 (gross)
• Shares owned after transaction: Not specified in the provided filing excerpt
• Footnote: F1 — automatic sale to cover tax obligations from RSU vesting (tax withholding)
• Filing date: 2026-02-10 (filed the next day; appears timely under Form 4 rules)

Context

• Tax-withholding sales tied to RSU vesting are common and typically routine administrative transactions; they do not necessarily signal the insider's view on the company's stock. This was not reported as an option exercise or a 10% owner transaction.