STRO Institutional Ownership
Who owns Sutro Biopharma, Inc. and what the big funds did with it last quarter, from every SEC 13F filing. 100 funds reported holding STRO at Jun 30, 2026, together owning 99.4% of the company.
- ▲65 buying vs 36 selling
- ▲Held by funds +12.5 pts
- ▲Funds holding +22
- ▼Superinvestors: 1 added, 3 cut
- ●Put/call not meaningful
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
8 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 100 | 78 | +28.2% |
| In funds' top 10 | 5 | 6 | −16.7% |
| 13F shares | 16.5M | 14.4M | +14.4% |
| Held by funds | 99.4% | 86.9% | +12.5 pts |
| New positions | 41 | 22 | +86.4% |
| Increased | 24 | 23 | +4.3% |
| Reduced | 18 | 13 | +38.5% |
| Sold out | 18 | 11 | +63.6% |
| Calls (shares) | 0 | 0 | – |
| Puts (shares) | 0 | 0 | – |
| Put/call ratio | – | – | – |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in STRO
All superinvestors →
Who owns STRO
share of fund held shares- Index and passive funds18.5%
- Active managers and hedge funds75.5%
- Banks and brokers5.9%
- Pensions, insurers and other0.1%
The top 10 holders own 57.8% of all STRO shares that funds reported. Groups are our own grouping of filers by name.
Filed so far for Q3 2026
8 funds changed their position- Sigma Planning CorpSold out−45K sh
- Y-Intercept (Hong Kong) LtdAdded+35K sh
- Mackenzie Financial CorpTrimmed−26K sh
- Achmea Investment Management B.V.New+12K sh
- State of WyomingAdded+464 sh
🔒 Free account: see all 8.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | Perceptive Advisors LLC | 7.87% | 1.3M | $43.3M | +590K |
| 2 | Bvf Inc/il | 7.55% | 1.3M | $41.6M | 0 |
| 3 | Affinity Asset Advisors, LLC | 7.07% | 1.2M | $38.9M | +103K |
| 4 | BlackRock, Inc. | 6.77% | 1.1M | $37.3M | +890K |
| 5 | Samsara Biocapital, LLC | 6.41% | 1.1M | $35.3M | 0 |
| 6 | Kynam Capital Management, LP | 5.26% | 873K | $29M | 0 |
| 7 | Orbimed Advisors LLC | 4.49% | 744K | $24.7M | −57K |
| 8 | Balyasny Asset Management L.P. | 4.29% | 711K | $23.6M | +245K |
| 9 | Vanguard Capital Management LLC | 4.19% | 694K | $23M | −26K |
| 10 | Eventide Asset Management, LLC | 3.53% | 585K | $19.4M | −130K |
- BlackRock, Inc.+890K sh+$29.5M
- Perceptive Advisors LLC+590K sh+$19.6M
- Merck & Co., Inc.+272K sh+$9M
- State Street Corp+254K sh+$8.4M
- Balyasny Asset Management L.P.+245K sh+$8.1M
- Ameriprise Financial Inc+245K sh+$8.1M
- Geode Capital Management, LLC+218K sh+$7.2M
- Vanguard Portfolio Management LLC+198K sh+$6.6M
- RA Capital Management, L.P.−715K sh−$17.8M
- Point72 Asset Management, L.P.−454K sh−$15.1M
- Merck & Co., Inc.−272K sh−$6.8M
- UBS Group AG−184K sh−$6.1M
- Adage Capital Partners Gp, L.l.c.−200K sh−$5M
- Opaleye Management Inc.−191K sh−$4.7M
- Eventide Asset Management, LLC−130K sh−$4.3M
- ADAR1 Capital Management, LLC−120K sh−$4M
STRO institutional ownership FAQ
Who owns the most STRO stock?
In Q2 2026 13F filings the largest holder of STRO was Perceptive Advisors LLC, followed by Bvf Inc/il and Affinity Asset Advisors, LLC. Index fund managers are usually the biggest holders of large companies.
What percentage of STRO is owned by institutions?
Funds that file 13F reports held 99.4% of STRO's shares at Jun 30, 2026, compared with 86.9% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying STRO?
In Q2 2026, 65 funds bought STRO (41 of them new positions) and 36 sold (18 sold out completely). Among well known investors, 1 added and 3 cut. Our fund sentiment for STRO is bullish.
What is STRO's institutional put/call ratio?
Too few option positions were reported for a meaningful ratio.
How current is this STRO ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.