Upstream Bio, Inc.
Ownership
Ownership Structure
Who owns Upstream Bio, Inc. (UPB)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 78.2% of the shares are freely tradable; institutional investors hold 89.5%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FMR Inc | 14.79 | 8,101,563 | +7.8 | 03/31/2026 |
| Orbimed Advisors LLC | 10.40 | 5,693,589 | +0.0 | 03/31/2026 |
| NORGES BANK | 6.88 | 3,768,619 | +30.7 | 06/30/2026 |
| BlackRock Inc | 6.15 | 3,370,689 | +0.8 | 03/31/2026 |
| Decheng Capital LLC | 4.98 | 2,724,868 | -13.3 | 03/31/2026 |
| Enavate Sciences GP, LLC | 4.49 | 2,459,703 | +0.0 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.42 | 1,873,574 | +0.0 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.63 | 1,443,025 | +0.0 | 07/31/2026 |
| Fidelity Small Cap Growth | 2.50 | 1,371,372 | +0.0 | 06/30/2026 |
| Fidelity Stock Selector Small Cap | 2.41 | 1,321,800 | +0.0 | 06/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Sutherland Everett Rand | Chief Executive Officer | 68,717 | 364,200 $ | Sep 16, 2026 | direct |
| Deykin Aaron | Chief Medical Officer | 32,302 | 171,201 $ | Sep 16, 2026 | direct |
| Gray Michael | CFO and COO | 27,942 | 148,093 $ | Sep 16, 2026 | direct |
| Houghton Adam | Chief Business Officer | 22,901 | 121,375 $ | Sep 16, 2026 | direct |
| Ambrose Allison | General Counsel | 15,563 | 82,484 $ | Sep 16, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 16, 2026 | Deykin Aaron | Chief Medical Officer | Sell | 895 | 5.49 | 4,914 |
| Sep 16, 2026 | Sutherland Everett Rand | Chief Executive Officer | Sell | 2,095 | 5.49 | 11,502 |
| Sep 16, 2026 | Houghton Adam | Chief Business Officer | Sell | 700 | 5.49 | 3,843 |
| Sep 16, 2026 | Gray Michael | CFO and COO | Sell | 853 | 5.49 | 4,683 |
| Sep 16, 2026 | Ambrose Allison | General Counsel | Sell | 485 | 5.49 | 2,663 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 18, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.