GRAY MICHAEL 4
4 · Upstream Bio, Inc. · Filed Mar 17, 2026
Research Summary
AI-generated summary of this filing
Upstream Bio (UPB) CFO/COO Michael Gray Sells 852 Shares
What Happened
Michael Gray, Upstream Bio’s (UPB) Chief Financial Officer and Chief Operating Officer, reported a sale of 852 shares on 2026-03-16. The shares were sold at $9.29 per share for total proceeds of approximately $7,915. The filing lists the transaction as a sale (code S).
Key Details
- Transaction date and price: 2026-03-16, 852 shares at $9.29 each (total ≈ $7,915)
- Transaction type: Reported as "Open market or private sale" (Sale, code S)
- Footnote: The sale was an automatic "sell-to-cover" to satisfy tax withholding on vested restricted stock units (RSUs); not at the insider’s discretion.
- Filing timeliness: Reported on Form 4 filed 2026-03-17 (next business day), which is timely under Form 4 rules.
- Shares owned after transaction: Not specified in the provided filing excerpt.
Context
Sell-to-cover transactions are routine administrative sales to cover tax withholding when RSUs vest; they generally reflect tax obligations rather than a discretionary decision to divest significant holdings. This is distinct from open-market purchases, which some investors view as a stronger signal of insider confidence.
Insider Transaction Report
Form 4
GRAY MICHAEL
CFO and COO
Transactions
- Sale
Common Stock
[F1]2026-03-16$9.29/sh−852$7,915→ 29,648 total
Footnotes (1)
- [F1]The Issuer has adopted a "sell-to-cover" policy to satisfy the tax withholding obligations of the Reporting Person. The sales reported on this Form 4 represent the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. Such sales were automatic and not at the discretion of the Reporting Person.
Signature
/s/ Allison Ambrose, Attorney-in-Fact|2026-03-17