As of the latest Form 4 filed Oct 16, 2025.
What Sutro Biopharma insiders — officers, directors and 10% owners — have bought and sold in their own stock, straight from their SEC Form 4 filings. Values are shares × the reported transaction price where both are disclosed.
Buys plotted up, sells down; bar height is the disclosed dollar value (shares × reported price). Our Form 4 history is only complete from mid-2026, so early months are sparse — the series fills in as more filings land. Open-market purchases and sales only.
Newest filing first — the 11 most recent filings for STRO.
| Filed | Trade date | Insider | Transaction | Shares | Price | Value | 10b5-1 | Filing |
|---|---|---|---|---|---|---|---|---|
| 2025-10-16 | 2025-10-15 | Pauling David Chief Admin. Ofcr. & GC | PPurchase | +12.5K | $0.80 | $9.99K | No | Form 4 ↗ |
| 2025-10-16 | 2025-10-15 | Gerber Hans-Peter CHIEF SCIENTIFIC OFFICER | PPurchase | +17.0K | $0.80 | $13.6K | No | Form 4 ↗ |
| 2025-10-16 | 2025-10-15 | Chung Jane Chief Executive Officer | PPurchase | +12.5K | $0.80 | $10.0K | No | Form 4 ↗ |
| 2025-10-16 | 2025-10-15 | Chow Gregory K. CFO | PPurchase | +19.8K | $0.81 | $16.0K | No | Form 4 ↗ |
| 2025-10-16 | 2025-10-15 | MATSUI CONNIE Director | PPurchase | +50.0K | $0.80 | $40.0K | No | Form 4 ↗ |
| 2025-09-22 | 2025-09-18 | Gerber Hans-Peter CHIEF SCIENTIFIC OFFICER | FTax | −13.4K | $0.90 | $12.1K | No | Form 4 ↗ |
| 2025-09-22 | 2025-09-18 | Gerber Hans-Peter, CHIEF SCIENTIFIC OFFICER | MExercise | +37.5K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2025-08-26 | 2025-08-09 | Chung Jane Chief Executive Officer | FTax | −6.71K | $0.80 | $5.37K | No | Form 4 ↗ |
| 2025-08-26 | 2025-08-09 | Chung Jane, Chief Executive Officer | MExercise | +18.8K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2025-08-26 | 2025-07-08 | Leyman Barbara Chief Business Officer | FTax | −8.94K | $0.78 | $6.98K | No | Form 4 ↗ |
| 2025-08-26 | 2025-07-08 | Leyman Barbara, Chief Business Officer | MExercise | +25.0K | $0.00 | $0.00 | No | Form 4 ↗ |
Insiders — a company’s officers, directors and holders of more than 10% of its stock — must report any trade in that stock to the SEC on a Form 4 within two business days. Each row here is one transaction from those filings.
The transaction code tells you what happened: Purchase (P) and Sale (S) are open-market trades — the ones markets watch most; Award (A) is a granted stock or unit, Option exercise (M) converts options into shares, and Gift (G) is a transfer for no consideration. Awards, exercises and gifts are largely compensation or administrative, not a directional bet.
One caveat on sales: many are made under a Rule 10b5-1 plan scheduled months in advance, so a sale is not automatically a bearish signal. Insider activity is a noisy input — read it alongside the filings, not on its own.
See also STRO’s full analysis or the market-wide insider trading feed. The tabs above jump to STRO’s other SEC data.
Source: SEC Form 4 filings for STRO, parsed from EDGAR. Transaction prices are as reported in the filing — SEC public-domain data, not market quotes. Values are shares × reported price where both are disclosed; grants and gifts often carry no price. A delayed record of what insiders reported, not a live position or a recommendation.
Research and education only — not financial advice. TENKis not a registered investment adviser or broker-dealer and gives no personalized advice. Every call is impersonal — identical for all users, generated on a schedule from SEC filings plus a delayed/third-party price feed — may be wrong or out of date, and is not a recommendation to buy or sell any security. The operator and an affiliated trading operation may hold or trade the securities TENK rates; see Disclosures. Past performance does not guarantee future results. Do your own research.