Deykin Aaron 4
4 · Upstream Bio, Inc. · Filed Mar 17, 2026
Research Summary
AI-generated summary of this filing
Upstream Bio (UPB) CMO Aaron Deykin Sells 894 Shares
What Happened Aaron Deykin, Chief Medical Officer of Upstream Bio (UPB), sold 894 shares on 2026-03-16 at $9.29 per share, generating proceeds of about $8,305. The sale was reported as a disposition (Code S) and reflects shares sold to cover tax withholding related to vested restricted stock units, not a discretionary open-market investment decision.
Key Details
- Transaction date and price: 2026-03-16, 894 shares at $9.29 each.
- Gross proceeds: approximately $8,305.
- Shares owned after transaction: not specified in this Form 4.
- Footnote: Issuer adopted a "sell-to-cover" policy—these sales were automatic to satisfy tax withholding on RSU vesting and were not at the Reporting Person's discretion (Footnote F1).
- Filing timeliness: Report filed 2026-03-17 (timely; within required reporting window).
Context Sell-to-cover transactions are routine tax-withholding actions when restricted stock units vest; they generally do not indicate a judgment about the company's prospects. For retail investors, purchases tend to be more informative than small, automatic sales like this one.
Insider Transaction Report
Form 4
Deykin Aaron
Chief Medical Officer
Transactions
- Sale
Common Stock
[F1]2026-03-16$9.29/sh−894$8,305→ 32,687 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