Updated Jul 16, 2026 · Last SEC filing 2026-06-09
SUTRO BIOPHARMA, INC. (STRO) has filed 9 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-06-09. 2 Form 8-K material event filings were reported by STRO in the last 90 days. InsiderAlpha tracks every STRO SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SIC classification | Biological Products, (No Diagnostic Substances) (SIC 2836) |
|---|---|
| SEC CIK | 0001382101 |
| Form 4 filings (90d) | 9 |
|---|---|
| Form 8-K filings (90d) | 2 |
| Latest Form 4 filing | 2026-06-09 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Chow Gregory K. | CFO | M — Option exercise | 2.5K | $0.00 | — | SEC | |
| Pauling David | Chief Admin. Ofcr. & GC | M — Option exercise | 675 | $0.00 | — | SEC | |
| Pauling David | Chief Admin. Ofcr. & GC | F — Tax withholding / forfeiture | 277 | $21.31 | $6K | SEC | |
| Chung Jane | Chief Executive Officer | M — Option exercise | 788 | $0.00 | — | SEC | |
| Chung Jane | Chief Executive Officer | F — Tax withholding / forfeiture | 282 | $21.31 | $6K | SEC | |
| Chung Jane | Chief Executive Officer | M — Option exercise | 7.8K | $0.00 | — | SEC | |
| Gerber Hans-Peter | CHIEF SCIENTIFIC OFFICER | M — Option exercise | 2.8K | $0.00 | — | SEC | |
| Chung Jane | Chief Executive Officer | F — Tax withholding / forfeiture | 2.8K | $20.55 | $57K | SEC | |
| Gerber Hans-Peter | CHIEF SCIENTIFIC OFFICER | F — Tax withholding / forfeiture | 1.2K | $20.55 | $24K | SEC | |
| Pauling David | Chief Admin. Ofcr. & GC | F — Tax withholding / forfeiture | 970 | $20.55 | $20K | SEC | |
| Pauling David | Chief Admin. Ofcr. & GC | M — Option exercise | 2.4K | $0.00 | — | SEC | |
| Chung Jane | Chief Executive Officer | M — Option exercise | 2.5K | $0.00 | — | SEC | |
| Gerber Hans-Peter | CHIEF SCIENTIFIC OFFICER | M — Option exercise | 1.1K | $0.00 | — | SEC | |
| Chung Jane | Chief Executive Officer | F — Tax withholding / forfeiture | 1.3K | $20.47 | $26K | SEC | |
| Pauling David | Chief Admin. Ofcr. & GC | M — Option exercise | 500 | $0.00 | — | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for SUTRO BIOPHARMA, INC. (STRO). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| Chow Gregory K. | 2 | — |
| PANEK JAMES P | 1 | — |
| Petree Daniel H | 1 | — |
| Dybbs Michael | 1 | — |
| Lobacki Joseph M | 1 | — |
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in STRO insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
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