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STRO

Sutro Biopharma, Inc.

Company with tickers: STRO

CIK
1382101
CUSIP
869367201
Shares Outstanding
16,570,439
13F Activity (30d)
59 filings 58 filers

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 71
Total Value: $352,644,852
Total Shares: 14,156,760

Institutional Ownership Trend

2 quarters

Holder Concentration

Across 71 13F filers · Δ vs Dec 31, 2025
Top Holder
8.8%
Dec 2025 → Mar 2026 · range 8.8% – 14.1%
−5.3 pts
Top 5
35.7%
Dec 2025 → Mar 2026 · range 35.7% – 44.5%
−8.7 pts
Top 10
60.9%
Dec 2025 → Mar 2026 · range 60.9% – 66.9%
−6.0 pts
HHI
472
Dec 2025 → Mar 2026 · range 472 – 607
Broadly held−135

Quarterly Activity

vs Dec 31, 2025
New
25
Increased
23
Decreased
12
Sold Out
10
Unchanged
11
Holder count: +15
Institutional value: +474.2%
Shares held: +166.7%

Top Buyers

vs Dec 31, 2025
Institution Added Now Holds Open

Top Sellers

vs Dec 31, 2025
Institution Sold Now Holds Open

Top New Positions

vs Dec 31, 2025
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Dec 31, 2025
Institution Previously Held Last Value (USD) Open
Showing 73 of 73
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Holder Value (USD) % of 13F Shares Open