Form4insider filings, from the source

Insider holders · CIK 0002022626

Upstream Bio, Inc. · UPB

Every insider with a reported Table I holding at this company, ranked by their last-reported share count. A balance is only as fresh as its filing — the report date sits next to every row on purpose. ← Back to activity

InsiderDirect sharesIndirect sharesTotal reportedLast report (ET)From
Everett Rand SutherlandChief Executive Officer68,717—68,717Sep 17, 2026 · 4:05 pm EDTForm 4
Aaron DeykinChief Medical Officer32,302—32,302Sep 17, 2026 · 4:05 pm EDTForm 4
Michael GrayCFO and COO27,942—27,942Sep 17, 2026 · 4:05 pm EDTForm 4
Adam HoughtonChief Business Officer22,901—22,901Sep 17, 2026 · 4:05 pm EDTForm 4
Allison AmbroseGeneral Counsel15,563—15,563Sep 17, 2026 · 4:05 pm EDTForm 4

Balances come from each insider’s most recent filing that reports a Table I holding; an insider who left the company years ago still appears with their last-known figure and its date. Indirect totals collapse multiple vehicles (trusts, LLCs) into one number — open the filing for the breakdown. Shares as filed, not split-adjusted.