Sutro Biopharma, Inc.
STRO- Exchange
- Nasdaq
- Industry
- Biological Products, (No Diagnostic Substances)
- SEC CIK
- 0001382101
No open-market purchases or sales by Sutro Biopharma, Inc. insiders were filed in the last 90 days; 100 institutions reported holding it in 13F filings for Q2 2026, worth $545.7M in total; no superinvestor holds it.
Holders of 5% or more of STRO
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Sutro Biopharma, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Affinity Asset Advisors, LLC | 13G | 7.77%6.58M shares | New | Oct 23, 20251 filing | Oct 23, 2025 | SEC |
| Suvretta Capital Management, LLC | 13G/A | 7.70%6.49M shares | – | Aug 13, 20251 filing | Aug 13, 2025 | SEC |
| Biotechnology Value Fund L P | 13G | 7.60%1.25M shares | New | Feb 18, 20261 filing | Feb 18, 2026 | SEC |
| Kynam Capital Management, LP | 13G | 6.44%0 shares | New | May 15, 20251 filing | May 15, 2025 | SEC |
| Millennium Management LLC | 13G | 5.60%4.72M shares | New | Jun 30, 20251 filing | Jun 30, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
10 Schedule 13D and 13G filings on Sutro Biopharma, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Feb 18, 20267:49 PM ET | Biotechnology Value Fund L Pand 9 others | 13G | 7.60%1.25M shares | New | Feb 10, 2026 | SEC |
| Oct 23, 20254:07 PM ET | Affinity Asset Advisors, LLCand 1 other | 13G | 7.77%6.58M shares | New | Oct 16, 2025 | SEC |
| Aug 14, 20256:10 PM ET | Ra Capital Management, L.P.and 3 others | 13G/A | 0.00%0 shares | −5.30 ppfrom 5.30%Below 5% | Jun 30, 2025 | SEC |
| Aug 13, 20258:47 PM ET | Suvretta Capital Management, LLCand 2 others | 13G/A | 7.70%6.49M shares | – | Jun 30, 2025 | SEC |
| Jul 29, 20252:41 PM ET | Vanguard Group Inc | 13G/A | 4.87%4.12M shares | –Below 5% | Jun 30, 2025 | SEC |
| Jul 16, 20257:02 PM ET | BlackRock, Inc. | 13G/A | 2.50%2.09M shares | −4.80 ppfrom 7.30%Below 5% | Jun 30, 2025 | SEC |
| Jun 30, 20254:36 PM ET | Millennium Management LLCand 2 others | 13G | 5.60%4.72M shares | New | Jun 27, 2025 | SEC |
| May 15, 202511:39 AM ET | Kynam Capital Management, LPand 2 others | 13G | 6.44%0 shares | New | Mar 31, 2025 | SEC |
| Apr 17, 20259:35 AM ET | BlackRock, Inc. | 13G/A | 7.30%6.14M shares | – | Mar 31, 2025 | SEC |
| Apr 4, 20254:32 PM ET | Ra Capital Management, L.P.and 3 others | 13G | 5.30%4.43M shares | New | Mar 28, 2025 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Sutro Biopharma, Inc. shares.
No Form 144 notices for Sutro Biopharma, Inc. are on file.