Upstream Bio, Inc. (UPB)
Nasdaq: UPB · Pharmaceutical Preparations · Waltham, MA · filing with the SEC since 2024
Who owns Upstream Bio, Inc.
As filed with the SECHolders of 5% or more
4
Fmr LLC holds 14.8% of COMMON STOCK, as its SCHEDULE 13G/A filed Aug 6, 2025 says.
Directors and officers
11
report now, of 15 people on the record since 2024. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 4 named at left.
Holders of 5% or moreshare of the class, as filed
Fmr LLC
SCHEDULE 13G/A · filed Aug 6, 2025 · COMMON STOCK · 13.4% in Feb 12, 2025
Norges Bank
SCHEDULE 13G/A · filed Aug 12, 2026 · Common Stock · 5.3% in Oct 24, 2025
Blackrock, Inc.
SCHEDULE 13G · filed Jul 30, 2026 · Common Stock
Decheng Capital Global Life Sciences Fund IV, L.P.
SCHEDULE 13G/A · filed May 15, 2026 · Common Stock, par value $0.001 per share · 6.1% in Feb 14, 2025
HBM Healthcare Investments (Cayman) Ltd.
SCHEDULE 13G/A · filed Nov 14, 2025 · Common Stock, par value $0.001 per share · reported falling below 5%, from 5.1% in Feb 13, 2025
TCG Crossover GP I, LLC
SCHEDULE 13G/A · filed Nov 14, 2025 · Common Stock, par value $0.001 per share · reported falling below 5%, from 5.2% in Feb 14, 2025
What UPB reports owning in othersstakes of 5% or more, and other ties
Upstream Bio, Inc. reports no stake in another company in the record.
Insider tradesForm 4
15sales
0purchases
0sales on a scheduled plan
5people selling
$100,000sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Sep 30, 2025 to Sep 30, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2026 runs to Sep 30, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window5 of 21 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Sutherland Everett Rand | Chief Executive Officer | 3 | $0 | 0 | 0 | $0 |
| Gray Michael | CFO and COO | 3 | $0 | 0 | 0 | $0 |
| Deykin Aaron | Chief Medical Officer | 3 | $0 | 0 | 0 | $0 |
| Houghton Adam | Chief Business Officer | 3 | $0 | 0 | 0 | $0 |
| Ambrose Allison | General Counsel | 3 | $0 | 0 | 0 | $0 |