UPSTREAM BIO INC UPB
COM · Common Stock · CUSIP 91678A107
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersWaltham, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($627.0k this quarter). Holder counts are more reliable. Shares outstanding: 54.8m as of 2026-08-04, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $6.92. Options: 4 managers hold calls ($268.5k notional), 1 hold puts ($9.7k).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q4 2024 | 71 |
| Q1 2025 | 80 |
| Q2 2025 | 84 |
| Q3 2025 | 95 |
| Q4 2025 | 134 |
| Q1 2026 | 141 |
| Q2 2026 | 149 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2025 | 34 | 37 |
| Q2 2025 | 54 | 23 |
| Q3 2025 | 60 | 31 |
| Q4 2025 | 83 | 41 |
| Q1 2026 | 87 | 72 |
| Q2 2026 | 101 | 57 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $8.0m | $520.2k | 0.06 |
| Q4 2025 | $1.5m | $841.6k | 0.58 |
| Q1 2026 | $972.0k | $872.1k | 0.90 |
| Q2 2026 | $268.5k | $9.7k | 0.04 |
Biggest buyers
| JPMORGAN CHASE & CO | Added | +549.0k |
| Walleye Capital LLC | New | +498.5k |
| AQR CAPITAL MANAGEMENT LLC | Added | +472.7k |
| BNP PARIBAS FINANCIAL MARKETS | Added | +385.5k |
| BlackRock, Inc. | Added | +382.7k |
| Qube Research & Technologies Ltd | Added | +359.2k |
| BANK OF AMERICA CORP /DE/ | Added | +343.3k |
| DIMENSIONAL FUND ADVISORS LP | Added | +301.6k |
| Trexquant Investment LP | Added | +289.8k |
| Voleon Capital Management LP | New | +285.2k |
Biggest sellers
| FEDERATED HERMES, INC. | Sold out | -979.8k |
| Pictet Asset Management Holding SA | Sold out | -733.4k |
| HSBC HOLDINGS PLC | Reduced | -629.5k |
| Nantahala Capital Management, LLC | Sold out | -400.0k |
| SAMSARA BIOCAPITAL, LLC | Reduced | -382.3k |
| Y-Intercept (Hong Kong) Ltd | Reduced | -307.1k |
| Alyeska Investment Group, L.P. | Sold out | -298.3k |
| Bain Capital Life Sciences Investors, LLC | Reduced | -266.3k |
| Prosight Management, LP | Sold out | -241.1k |
| TCG Crossover Management, LLC | Sold out | -181.1k |
Biggest calls
| CITADEL ADVISORS LLC | Reduced | $103.8k15.0k shares |
| JANE STREET GROUP, LLC | New | $82.3k11.9k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $69.9k10.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $12.5k1.8k shares |
Biggest puts
| SIMPLEX TRADING, LLC | Reduced | $9.7k1.4k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution +1.4 pts · filed 2025-08-06 | 14.8% |
| NORGES BANK 13G · institution +2.4 pts · filed 2026-08-12 | 7.7% |
| BlackRock, Inc. 13G · institution new · filed 2026-07-30 | 5.2% |
| Decheng Capital Global Life Sciences Fund IV, L.P. 13G · exempt (held before listing) -1.1 pts · filed 2026-05-15 | 5.0% |
Fell to 5% or below in the last year: HBM Healthcare Investments (Cayman) Ltd. (4.1%, 2025-11-14), TCG Crossover GP I, LLC (3.9%, 2025-11-14)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 2 | $14.0m | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 5 | $46.6k | — |
| Q2 2026 | 0 | — | 5 | $30.6k | — |
| Q3 2026 | 0 | — | 5 | $27.6k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-16 | Sutherland Everett Rand Chief Executive Officer, director | Sold | $11.5k2.1k shares |
| 2026-09-16 | Deykin Aaron Chief Medical Officer | Sold | $4.9k895 shares |
| 2026-09-16 | GRAY MICHAEL CFO and COO | Sold | $4.7k853 shares |
| 2026-09-16 | Houghton Adam Chief Business Officer | Sold | $3.8k700 shares |
| 2026-09-16 | Ambrose Allison General Counsel | Sold | $2.7k485 shares |
| 2026-06-16 | Sutherland Everett Rand Chief Executive Officer, director | Sold | $12.8k2.1k shares |
| 2026-06-16 | Deykin Aaron Chief Medical Officer | Sold | $5.5k895 shares |
| 2026-06-16 | GRAY MICHAEL CFO and COO | Sold | $5.2k853 shares |
| 2026-06-16 | Houghton Adam Chief Business Officer | Sold | $4.3k700 shares |
| 2026-06-16 | Ambrose Allison General Counsel | Sold | $2.9k477 shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.00% of their portfolio | 8.2m $56.5m | Added +61.3k |
| ORBIMED ADVISORS LLC 0.75% of their portfolio | 5.7m $39.4m | Unchanged |
| NORGES BANK 0.00% of their portfolio | 3.8m $26.1m | Not comparable |
| BlackRock, Inc. 0.00% of their portfolio | 3.8m $26.0m | Added +382.7k |
| Decheng Capital LLC 2.58% of their portfolio | 2.7m $18.9m | Unchanged |
| ENAVATE SCIENCES GP, LLC 4.93% of their portfolio | 2.5m $17.0m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.9m $13.0m | Added +3.2k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 1.1m $7.9m | Added +206.5k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 1.0m $7.2m | Added +215.6k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 1.0m $7.0m | Added +549.0k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 978.5k $6.8m | Added +359.2k |
| Parkman Healthcare Partners LLC 0.66% of their portfolio | 935.2k $6.5m | Added +148.5k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 931.3k $6.4m | Reduced -19.4k |
| SEB Asset Management AB 0.02% of their portfolio | 878.5k $6.1m | Unchanged |
| Woodline Partners LP 0.02% of their portfolio | 831.5k $5.8m | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 766.3k $5.3m | Added +61.0k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 712.7k $4.9m | Reduced -15.0k |
| Y-Intercept (Hong Kong) Ltd 0.09% of their portfolio | 693.6k $4.8m | Reduced -307.1k |
| Bain Capital Life Sciences Investors, LLC 0.25% of their portfolio | 600.9k $4.2m | Reduced -266.3k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 544.9k $3.8m | Added +472.7k |
| MORGAN STANLEY 0.00% of their portfolio | 524.6k $3.6m | Reduced -28.0k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 511.5k $3.5m | Added +385.5k |
| Walleye Capital LLC 0.02% of their portfolio | 498.5k $3.4m | New |
| Trexquant Investment LP 0.02% of their portfolio | 466.4k $3.2m | Added +289.8k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 453.0k $3.1m | Added +274.8k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 391.8k $2.7m | Added +343.3k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 381.6k $2.6m | Added +301.6k |
| Altshuler Shaham Ltd 0.03% of their portfolio | 380.1k $2.6m | Unchanged |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.00% of their portfolio | 357.8k $2.5m | Added +172.7k |
| SAMSARA BIOCAPITAL, LLC 0.20% of their portfolio | 353.7k $2.4m | Reduced -382.3k |
| Propel Bio Management, LLC 1.27% of their portfolio | 350.4k $2.4m | Added +8.6k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 342.4k $2.4m | Unchanged |
| NORTHERN TRUST CORP 0.00% of their portfolio | 297.3k $2.1m | Added +36.4k |
| Squarepoint Ops LLC 0.00% of their portfolio | 290.9k $2.0m | Added +246.3k |
| Voleon Capital Management LP 0.04% of their portfolio | 285.2k $2.0m | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 262.5k $1.8m | Added +4.7k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.01% of their portfolio | 253.1k $1.8m | New |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 246.9k $1.7m | Reduced -69.7k |
| XTX Topco Ltd 0.02% of their portfolio | 242.3k $1.7m | Added +33.1k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 241.4k $1.7m | Added +60.6k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 239.6k $1.7m | Added +15.5k |
| UBS Group AG 0.00% of their portfolio | 234.7k $1.6m | Added +3.5k |
| Schonfeld Strategic Advisors LLC 0.01% of their portfolio | 225.8k $1.6m | Added +64.4k |
| Jump Financial, LLC 0.01% of their portfolio | 223.2k $1.5m | Reduced -96.2k |
| SPHERA FUNDS MANAGEMENT LTD. 0.22% of their portfolio | 219.7k $1.5m | Reduced -138.3k |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 175.1k $1.2m | New |
| HRT FINANCIAL LP 0.00% of their portfolio | 170.6k $1.2m | New |
| Boxer Capital Management, LLC 0.08% of their portfolio | 150.0k $1.0m | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 131.3k $908.6k | Added +69.2k |
| EntryPoint Capital, LLC 0.22% of their portfolio | 129.4k $895.8k | Added +55.9k |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 118.6k $820.9k | New |
| Bank of New York Mellon Corp 0.00% of their portfolio | 85.7k $593.4k | Added +4.4k |
| Nuveen, LLC 0.00% of their portfolio | 84.8k $586.6k | Added +9.2k |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 78.2k $541.1k | Reduced -9.4k |
| Man Group plc 0.00% of their portfolio | 73.8k $510.9k | Added +52.7k |
| GSA CAPITAL PARTNERS LLP 0.03% of their portfolio | 69.3k $480.0k | Added +30.1k |
| Simplify Asset Management Inc. 0.01% of their portfolio | 62.1k $429.8k | Reduced -15.7k |
| ALPS ADVISORS INC 0.00% of their portfolio | 55.2k $382.2k | Added +11.2k |
| Quantinno Capital Management LP 0.00% of their portfolio | 54.8k $379.5k | Added +5.4k |
| Virtus Investment Advisers, LLC 0.09% of their portfolio | 53.6k $371.2k | Added +43.6k |
| Invesco Ltd. 0.00% of their portfolio | 53.4k $369.5k | Added +12.9k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 51.7k $465.1k | Added +20.7k |
| Brevan Howard Capital Management LP 0.00% of their portfolio | 50.4k $348.6k | New |
| Swiss National Bank 0.00% of their portfolio | 48.1k $332.9k | Unchanged |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 47.5k $329.0k | Added +43.9k |
| Allspring Global Investments Holdings, LLC 0.00% of their portfolio | 43.2k $298.8k | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 42.4k $293.3k | Added +1.2k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 42.3k $292.9k | New |
| ExodusPoint Capital Management, LP 0.00% of their portfolio | 41.0k $284.0k | Reduced -50.4k |
| CITIGROUP INC 0.00% of their portfolio | 40.3k $279.1k | Added +35.3k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 38.6k $267.3k | Reduced -1.0k |
| Stonepine Capital Management, LLC 0.18% of their portfolio | 33.4k $231.3k | Reduced -1.6k |
| Mariner, LLC 0.00% of their portfolio | 33.1k $229.3k | Added +5.8k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 29.5k $204.1k | Added +11.1k |
| BARCLAYS PLC 0.00% of their portfolio | 29.2k $202.1k | Added +4.5k |
| Creative Planning 0.00% of their portfolio | 28.5k $197.1k | Added +17.6k |
| Quantbot Technologies LP 0.01% of their portfolio | 28.2k $195.0k | Added +27.5k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 28.1k $195.0k | Added +1.6k |
| AXQ CAPITAL, LP 0.02% of their portfolio | 27.1k $187.3k | Reduced -435 |
| nVerses Capital, LLC 0.26% of their portfolio | 24.0k $166.3k | New |
| DNB Asset Management AS 0.00% of their portfolio | 23.6k $163.3k | Added +85 |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 22.7k $157.2k | Added +13.5k |
| Graham Capital Management, L.P. 0.00% of their portfolio | 22.5k $155.8k | New |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 22.4k $154.9k | New |
| Verdad Advisers, LP 0.14% of their portfolio | 21.8k $150.9k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 20.9k $144.3k | Added +1.5k |
| SG Americas Securities, LLC 0.00% of their portfolio | 20.3k $141.0k | New |
| SEI INVESTMENTS CO 0.00% of their portfolio | 20.0k $138.6k | New |
| WINTON GROUP Ltd 0.00% of their portfolio | 19.8k $137.0k | New |
| IEQ CAPITAL, LLC 0.00% of their portfolio | 19.5k $135.2k | New |
| DIADEMA PARTNERS LP 0.05% of their portfolio | 19.1k $132.1k | Reduced -2.5k |
| Shay Capital LLC 0.01% of their portfolio | 18.0k $124.6k | Added +8.0k |
| Quadrature Capital Ltd 0.00% of their portfolio | 18.0k $124.5k | New |
| Entropy Technologies, LP 0.00% of their portfolio | 17.5k $121.4k | Reduced -5.8k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 17.1k $118.1k | Reduced -24.6k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 16.2k $112.2k | Added +609 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 15.7k $108.9k | Added +397 |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 15.6k $107.9k | New |
| MERCER GLOBAL ADVISORS INC /ADV 0.00% of their portfolio | 13.4k $92.4k | New |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 13.1k $90.4k | Unchanged |