Comparable stake leader
FMR LLC
SEC ownership of Upstream Bio, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0002022626.
Disclosed value leader
FMR LLC
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Public ticker
- UPB on Nasdaq
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
FMR LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
FMR LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
31 Mar 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0002022626
- Issuer location
- Waltham, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Upstream Bio, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
FMR LLC
Disclosed value leader
FMR LLC
Comparable rows
50/50
Latest evidence
31 Mar 2026
13D/G
13F
3/4/5
Lead comparable stake: 15%
13D/G row: FMR LLC
Showing 1-8 of 50 holder rows.
Quick read
FMR LLC leads the comparable SEC ownership view at 15%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens FMR LLC's linked filing trail.
Comparable ownership
Top 5
FMR LLC
15%
NORGES BANK
5.3%
Decheng Capital Global Life Scien...
5%
HBM Healthcare Investments (Cayma...
4.1%
TCG Crossover GP I, LLC
3.9%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FMR LLC |
13D/G
13F
Company
|
15%
|
$93,972,663
7,936,880 shares
|
+$9,006,605 | 30 Jun 2025 |
| NORGES BANK |
13D/G
|
5.3%
|
$54,226,626
2,882,647 shares
|
$0 | 30 Sep 2025 |
| Decheng Capital Global Life Sciences Fund IV, L.P. |
13D/G
|
5%
|
$25,886,246
2,724,868 shares
|
-$5,324,038 | 31 Mar 2026 |
| HBM Healthcare Investments (Cayman) Ltd. |
13D/G
|
4.1%
|
$41,290,257
2,195,111 shares
|
-$9,780,217 | 30 Sep 2025 |
| TCG Crossover GP I, LLC |
13D/G
|
3.9%
|
$39,822,919
2,117,103 shares
|
-$12,878,523 | 30 Sep 2025 |
| ORBIMED ADVISORS LLC |
13F
3/4/5
Company · Director, 10%+ Owner
|
10%
|
$51,242,301
5,693,589 shares
|
— | 31 Mar 2026 |
| BlackRock, Inc. |
13F
Company
|
6.2%
|
$30,336,201
3,370,689 shares
|
— | 31 Mar 2026 |
| Decheng Capital LLC |
13F
Company
|
5%
|
$24,523,812
2,724,868 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$77,193.
Buys
$0
Insiders: 0
Sells
$77,193
Insiders: 5
Net
-$77,193
Shares: -10,033
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 10,033
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 5,020 | $0 | $30,622 | -$30,622 |
| 3-6 | 0 | 5,013 | $0 | $46,571 | -$46,571 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-14 of 14 reporting-owner rows connected to Upstream Bio, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
14
Largest Forms 3/4/5 holder
Everett Rand Sutherland
Net 12M change
-$77,192
Latest report
16 Jun 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Everett Rand Sutherland | Chief Executive Officer, Director | $431,953 | -$32,223 | -6.9% | Filing P/S | 16 Jun 2026 |
| Aaron Deykin | Chief Medical Officer | $202,501 | -$13,765 | -6.4% | Filing P/S | 16 Jun 2026 |
| Michael Gray | CFO and COO | $175,649 | -$13,118 | -6.9% | Filing P/S | 16 Jun 2026 |
| Adam Houghton | Chief Business Officer | $143,966 | -$10,764 | -7% | Filing P/S | 16 Jun 2026 |
| Allison Ambrose | General Counsel | $97,892 | -$7,322 | -7% | Filing P/S | 16 Jun 2026 |
| Wellington Biomedical Innovation Master Investors (Cayman) II L.P. | 10%+ Owner | Mixed | 15 Oct 2024 | |||
| ORBIMED ADVISORS LLC | Director, 10%+ Owner | Mixed | 15 Oct 2024 | |||
| Liam Ratcliffe | Director | Mixed | 09 Jun 2026 | |||
| Marcella K. Ruddy | Director | Mixed | 09 Jun 2026 | |||
| Daniella Beckman | Director | Mixed | 09 Jun 2026 | |||
| AI Upstream LLC | 10%+ Owner | Mixed | 15 Oct 2024 | |||
| Erez Chimovits | Director | Mixed | 09 Jun 2026 | |||
| Harold Edward Fleming | Director | Mixed | 09 Jun 2026 | |||
| Ronald C. Renaud Jr. | Director | Mixed | 09 Jun 2026 |
Recent insider transactions for Upstream Bio, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Michael Gray | UPB | Common Stock | Sale | -2.88% | $5,203 | $6.10 | -853 | 28,795 | 16 Jun 2026 | Direct |
| Everett Rand Sutherland | UPB | Common Stock | Sale | -2.87% | $12,780 | $6.10 | -2,095 | 70,812 | 16 Jun 2026 | Direct |
| Adam Houghton | UPB | Common Stock | Sale | -2.88% | $4,270 | $6.10 | -700 | 23,601 | 16 Jun 2026 | Direct |
| Aaron Deykin | UPB | Common Stock | Sale | -2.63% | $5,460 | $6.10 | -895 | 33,197 | 16 Jun 2026 | Direct |
| Allison Ambrose | UPB | Common Stock | Sale | -2.89% | $2,910 | $6.10 | -477 | 16,048 | 16 Jun 2026 | Direct |
| Marcella K. Ruddy | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Ronald C. Renaud Jr. | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Harold Edward Fleming | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Daniella Beckman | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Liam Ratcliffe | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Erez Chimovits | UPB | Stock Option (Right to Buy) | Award | 17,096 | 17,096 | 09 Jun 2026 | Direct | |||
| Michael Gray | UPB | Common Stock | Sale | -2.79% | $7,915 | $9.29 | -852 | 29,648 | 16 Mar 2026 | Direct |
| Aaron Deykin | UPB | Common Stock | Sale | -2.66% | $8,305 | $9.29 | -894 | 32,687 | 16 Mar 2026 | Direct |
| Everett Rand Sutherland | UPB | Common Stock | Sale | -2.79% | $19,444 | $9.29 | -2,093 | 72,907 | 16 Mar 2026 | Direct |
| Allison Ambrose | UPB | Common Stock | Sale | -2.79% | $4,413 | $9.29 | -475 | 16,525 | 16 Mar 2026 | Direct |
| Adam Houghton | UPB | Common Stock | Sale | -2.8% | $6,494 | $9.29 | -699 | 24,301 | 16 Mar 2026 | Direct |
| Michael Gray | UPB | Common Stock | Award | 30,500 | 30,500 | 02 Jan 2026 | Direct | |||
| Michael Gray | UPB | Stock Option (Right to Buy) | Award | 91,500 | 91,500 | 02 Jan 2026 | Direct | |||
| Aaron Deykin | UPB | Common Stock | Award | 2024% | 32,000 | 33,581 | 02 Jan 2026 | Direct | ||
| Aaron Deykin | UPB | Stock Option (Right to Buy) | Award | 96,000 | 96,000 | 02 Jan 2026 | Direct | |||
| Allison Ambrose | UPB | Common Stock | Award | 17,000 | 17,000 | 02 Jan 2026 | Direct | |||
| Allison Ambrose | UPB | Stock Option (Right to Buy) | Award | 51,000 | 51,000 | 02 Jan 2026 | Direct | |||
| Adam Houghton | UPB | Common Stock | Award | 25,000 | 25,000 | 02 Jan 2026 | Direct | |||
| Adam Houghton | UPB | Stock Option (Right to Buy) | Award | 75,000 | 75,000 | 02 Jan 2026 | Direct | |||
| Everett Rand Sutherland | UPB | Common Stock | Award | 75,000 | 75,000 | 02 Jan 2026 | Direct | |||
| Everett Rand Sutherland | UPB | Stock Option (Right to Buy) | Award | 225,000 | 225,000 | 02 Jan 2026 | Direct |
* marks a reported price that did not pass the local price check.