Upstream Bio's three largest insider shareholders as of May 30, 2026 are Upstream Llc Ai (TenPercentOwner, 5.49Mn shares), Advisors Llc Orbimed (Director, 4.55Mn shares), Erez Chimovits (Director, 4.55Mn shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Advisors Llc Orbimed | - | 0 | 4,554,873 | 17 Oct, 2024 |
| Michael Gray | Cfo And Coo | 29,648 | 0 | 17 Mar, 2026 |
| Erez Chimovits | - | 0 | 4,554,873 | 17 Oct, 2024 |
| Everett Rand Sutherland | Chief Executive Officer | 72,907 | 0 | 17 Mar, 2026 |
| Biomedical Innovation Master Investors (Cayman) Ii L.P. Wellington | - | 894,733 | 0 | 15 Oct, 2024 |
| Adam Houghton | Chief Business Officer | 24,301 | 0 | 17 Mar, 2026 |
| Aaron Deykin | Chief Medical Officer | 32,687 | 0 | 17 Mar, 2026 |
| Upstream Llc Ai | - | 5,494,410 | 0 | 17 Oct, 2024 |
| Allison Ambrose | General Counsel | 16,525 | 0 | 17 Mar, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 16 Mar, 2026 | Allison Ambrose | Common Stock | D | 475 | $9.29 | 16,525 | D | S |
| 16 Mar, 2026 | Michael Gray | Common Stock | D | 852 | $9.29 | 29,648 | D | S |
| 16 Mar, 2026 | Everett Rand Sutherland | Common Stock | D | 2,093 | $9.29 | 72,907 | D | S |
| 16 Mar, 2026 | Adam Houghton | Common Stock | D | 699 | $9.29 | 24,301 | D | S |
| 16 Mar, 2026 | Aaron Deykin | Common Stock | D | 894 | $9.29 | 32,687 | D | S |
| 02 Jan, 2026 | Aaron Deykin | Common Stock | A | 32,000 | $0.00 | 33,581 | D | A |
| 02 Jan, 2026 | Michael Gray | Common Stock | A | 30,500 | $0.00 | 30,500 | D | A |
| 02 Jan, 2026 | Adam Houghton | Common Stock | A | 25,000 | $0.00 | 25,000 | D | A |
| 02 Jan, 2026 | Allison Ambrose | Common Stock | A | 17,000 | $0.00 | 17,000 | D | A |
| 02 Jan, 2026 | Everett Rand Sutherland | Common Stock | A | 75,000 | $0.00 | 75,000 | D | A |
| 02 Jan, 2026 | Michael Gray | Stock Option (Right to Buy) | A | 91,500 | $0.00 | 91,500 | D | A |
| 02 Jan, 2026 | Aaron Deykin | Stock Option (Right to Buy) | A | 96,000 | $0.00 | 96,000 | D | A |
| 02 Jan, 2026 | Adam Houghton | Stock Option (Right to Buy) | A | 75,000 | $0.00 | 75,000 | D | A |
| 02 Jan, 2026 | Everett Rand Sutherland | Stock Option (Right to Buy) | A | 225,000 | $0.00 | 225,000 | D | A |
| 02 Jan, 2026 | Allison Ambrose | Stock Option (Right to Buy) | A | 51,000 | $0.00 | 51,000 | D | A |
| 10 Jun, 2025 | Harold Edward Fleming | Stock Option (Right to Buy) | A | 17,096 | $0.00 | 17,096 | D | A |
| 10 Jun, 2025 | Ronald C Jr Renaud | Stock Option (Right to Buy) | A | 17,096 | $0.00 | 17,096 | D | A |
| 10 Jun, 2025 | Erez Chimovits | Stock Option (Right to Buy) | A | 17,096 | $0.00 | 17,096 | D | A |
| 10 Jun, 2025 | Marcella K. Ruddy | Stock Option (Right to Buy) | A | 17,096 | $0.00 | 17,096 | D | A |
| 10 Jun, 2025 | Liam Ratcliffe | Stock Option (Right to Buy) | A | 17,096 | $0.00 | 17,096 | D | A |