SUTRO BIOPHARMA INC STRO
COM SHS · Common Stock · CUSIP 869367201
- SectorHealth care
- IndustryBiological Products, (No Diagnostic Substances)
- HeadquartersSouth San Francisco, CA
- Founded2003
- Websitesutrobio.com
- 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. Holder counts are more reliable. Shares outstanding: 16.6m as of 2026-08-07, 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 ≈ $33.11. Options: 2 managers hold calls ($371.8k notional), 2 hold puts ($371.8k).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q4 2025 | 56 |
| Q1 2026 | 71 |
| Q2 2026 | 97 |
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 2026 | 44 | 21 |
| Q2 2026 | 65 | 32 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $0 | $0 | — |
| Q4 2025 | $34.7k | $8.1k | 0.23 |
| Q1 2026 | $0 | $2.2m | — |
| Q2 2026 | $371.8k | $371.8k | 1.00 |
Biggest buyers
| BlackRock, Inc. | Added | +890.0k |
| PERCEPTIVE ADVISORS LLC | Added | +589.5k |
| Merck & Co., Inc. | New | +272.4k |
| STATE STREET CORP | Added | +253.9k |
| Balyasny Asset Management L.P. | Added | +245.4k |
| AMERIPRISE FINANCIAL INC | New | +244.7k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +218.3k |
| VANGUARD PORTFOLIO MANAGEMENT LLC | New | +197.6k |
| Nuveen, LLC | New | +168.0k |
| JPMORGAN CHASE & CO | New | +159.6k |
Biggest sellers
| RA CAPITAL MANAGEMENT, L.P. | Sold out | -715.3k |
| Point72 Asset Management, L.P. | Reduced | -454.3k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Sold out | -200.0k |
| Opaleye Management Inc. | Sold out | -190.7k |
| UBS Group AG | Reduced | -184.4k |
| EVENTIDE ASSET MANAGEMENT, LLC | Reduced | -130.0k |
| ADAR1 Capital Management, LLC | Reduced | -120.4k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | -76.5k |
| Eversept Partners, LP | Sold out | -73.2k |
| Burkehill Global Management, LP | Sold out | -71.5k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $368.5k11.1k shares |
| SIMPLEX TRADING, LLC | New | $3.3k100 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $365.2k11.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $6.6k200 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 |
|---|---|
| PERCEPTIVE ADVISORS LLC 13G · passive investor +2.5 pts · filed 2026-08-14 | 7.9% |
| BIOTECHNOLOGY VALUE FUND L P 13G · passive investor new · filed 2026-02-18 | 7.6% |
| Affinity Asset Advisors, LLC 13G · institution -2.3 pts · filed 2026-05-14 | 6.5% |
| BlackRock, Inc. 13G · institution new · filed 2026-07-30 | 6.4% |
| Samsara BioCapital, L.P. 13G · passive investor new · filed 2026-05-15 | 6.4% |
Fell to 5% or below in the last year: Point72 Asset Management, L.P. (1.4%, 2026-08-14), MILLENNIUM MANAGEMENT LLC (1.3%, 2026-04-21)
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 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 5 | — | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
None reported since 1 Apr 2026.
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| PERCEPTIVE ADVISORS LLC 0.67% of their portfolio | 1.3m $43.3m | Added +589.5k |
| BVF INC/IL 1.06% of their portfolio | 1.3m $41.6m | Unchanged |
| Affinity Asset Advisors, LLC 1.90% of their portfolio | 1.2m $38.9m | Added +103.0k |
| BlackRock, Inc. 0.00% of their portfolio | 1.1m $37.3m | Added +890.0k |
| SAMSARA BIOCAPITAL, LLC 2.90% of their portfolio | 1.1m $35.3m | Unchanged |
| Kynam Capital Management, LP 1.60% of their portfolio | 872.6k $29.0m | Unchanged |
| ORBIMED ADVISORS LLC 0.47% of their portfolio | 743.9k $24.7m | Reduced -57.2k |
| Balyasny Asset Management L.P. 0.04% of their portfolio | 711.2k $23.6m | Added +245.4k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 694.2k $23.0m | Reduced -26.2k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.26% of their portfolio | 585.3k $19.4m | Reduced -130.0k |
| Velan Capital Investment Management LP 10.42% of their portfolio | 512.2k $17.0m | Unchanged |
| Woodline Partners LP 0.05% of their portfolio | 458.0k $15.2m | Added +588 |
| ADAR1 Capital Management, LLC 0.63% of their portfolio | 404.0k $13.4m | Reduced -120.4k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 389.7k $12.9m | Added +218.3k |
| ACADIAN ASSET MANAGEMENT LLC 0.01% of their portfolio | 373.8k $12.4m | Added +38.0k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 366.0k $12.2m | Added +155.6k |
| STATE STREET CORP 0.00% of their portfolio | 306.0k $10.2m | Added +253.9k |
| Merck & Co., Inc. 1.72% of their portfolio | 272.4k $9.0m | New |
| ACUTA CAPITAL PARTNERS, LLC 6.25% of their portfolio | 270.3k $9.0m | Added +826 |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 244.7k $8.1m | New |
| Point72 Asset Management, L.P. 0.01% of their portfolio | 237.8k $7.9m | Reduced -454.3k |
| KVP Capital Advisors, LP 5.52% of their portfolio | 226.6k $7.5m | Unchanged |
| UBS Group AG 0.00% of their portfolio | 208.5k $6.9m | Reduced -184.4k |
| TWO SIGMA INVESTMENTS, LP 0.01% of their portfolio | 201.7k $6.7m | Added +136.5k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 197.6k $6.6m | New |
| MARSHALL WACE, LLP 0.00% of their portfolio | 175.2k $5.8m | Reduced -47.4k |
| Nuveen, LLC 0.00% of their portfolio | 168.0k $5.6m | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 159.6k $5.3m | New |
| Seven Fleet Capital Management LP 0.63% of their portfolio | 159.1k $3.8m | New |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 149.2k $5.0m | Added +122.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 125.9k $4.2m | Added +92.8k |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 106.6k $3.5m | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 104.2k $3.5m | Added +9.4k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 102.0k $3.4m | Reduced -15.6k |
| MACKENZIE FINANCIAL CORP 0.00% of their portfolio | 94.8k $3.1m | New |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 86.3k $2.9m | Reduced -11.5k |
| Invesco Ltd. 0.00% of their portfolio | 57.3k $1.9m | Added +40.1k |
| Y-Intercept (Hong Kong) Ltd 0.04% of their portfolio | 55.9k $1.9m | New |
| Squarepoint Ops LLC 0.00% of their portfolio | 55.5k $1.8m | New |
| XTX Topco Ltd 0.02% of their portfolio | 52.2k $1.7m | Added +44.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 49.3k $1.6m | Added +38.7k |
| Sigma Planning Corp 0.04% of their portfolio | 45.0k $1.5m | Added +32.5k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 41.4k $1.4m | New |
| BARCLAYS PLC 0.00% of their portfolio | 37.0k $1.2m | Added +36.8k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 36.1k $1.2m | Added +17.3k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 35.3k $1.2m | Unchanged |
| Elmind Capital, LP 0.27% of their portfolio | 32.0k $1.1m | New |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 30.1k $1.0m | New |
| Trexquant Investment LP 0.01% of their portfolio | 27.6k $917.5k | Reduced -6.7k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 27.4k $909.1k | Added +27.3k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 20.6k $684.8k | New |
| GSA CAPITAL PARTNERS LLP 0.04% of their portfolio | 19.7k $656.0k | Reduced -6.1k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 16.4k $544.0k | New |
| Informed Momentum Co LLC 0.05% of their portfolio | 16.2k $538.9k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 15.6k $516.7k | New |
| RBF Capital, LLC 0.02% of their portfolio | 15.3k $507.0k | Unchanged |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 13.6k $452.0k | New |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 13.5k $449.7k | New |
| MORGAN STANLEY 0.00% of their portfolio | 12.4k $410.2k | Added +1.8k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 10.8k $358.6k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 9.4k $312.1k | New |
| Walleye Capital LLC 0.00% of their portfolio | 9.3k $309.0k | New |
| Integrated Quantitative Investments LLC 0.05% of their portfolio | 8.9k $296.8k | New |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 8.4k $279.7k | Reduced -76.5k |
| Lighthouse Investment Partners, LLC 0.01% of their portfolio | 8.4k $277.8k | New |
| CITIGROUP INC 0.00% of their portfolio | 7.5k $247.5k | Reduced -11.4k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 7.3k $242.8k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 7.3k $242.4k | New |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 7.0k $232.4k | New |
| Persistent Asset Partners Ltd 0.07% of their portfolio | 6.6k $218.1k | Reduced -842 |
| Verdad Advisers, LP 0.20% of their portfolio | 6.4k $212.5k | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 6.2k $205.7k | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 5.6k $185.9k | New |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 5.4k $180.8k | Reduced -1.7k |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 4.7k $156.2k | New |
| Legal & General Group Plc 0.00% of their portfolio | 3.5k $114.9k | New |
| State of Wyoming 0.01% of their portfolio | 1.6k $53.7k | New |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 1.4k $48.1k | New |
| FMR LLC 0.00% of their portfolio | 1.3k $44.5k | Added +289 |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 1.3k $42.3k | New |
| FNY Investment Advisers, LLC 0.01% of their portfolio | 1.0k $33.0k | Unchanged |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 866 $28.8k | New |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 687 $23.0k | Added +675 |
| Owl Creek Wealth Partners LLC 0.00% of their portfolio | 491 $16.3k | Unchanged |
| Sterling Capital Management LLC 0.00% of their portfolio | 281 $9.3k | New |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 220 $7.3k | New |
| Quantbot Technologies LP 0.00% of their portfolio | 201 $6.7k | New |
| Physician Wealth Advisors, Inc. 0.00% of their portfolio | 182 $6.0k | Unchanged |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 100 $3.3k | Reduced -1.2k |
| PNC Financial Services Group, Inc. 0.00% of their portfolio | 62 $2.1k | Unchanged |
| Avion Wealth 0.00% of their portfolio | 46 $1.0k | Reduced -26 |
| NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio | 44 $1.5k | Unchanged |
| HighMark Wealth Management LLC 0.00% of their portfolio | 23 $763 | Unchanged |
| Arax Advisory Partners 0.00% of their portfolio | 16 $531 | Reduced -25 |
| FIFTH THIRD BANCORP 0.00% of their portfolio | 2 $66 | Unchanged |
| Steward Partners Investment Advisory, LLC 0.00% of their portfolio | 2 $66 | New |
| Optiver Holding B.V. 0.00% of their portfolio | 2 $66 | New |