John Cox
CIK 1498428 · CEO & President · last filed 2026-08-17
John Cox is a CEO & President who has filed 82 SEC Form 4 insider transactions across 5 companies since 2010. The most recent filing shows the insider sold $131.0K of DYN on Aug 17, 2026. Across all open-market trades the lifetime net is −$13.2M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $18.4M across reported positions.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
$18.36M
5
82
-$13.24M
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| DYN | CEO & President | 381,165 | $26.00 | $9.91M | $1.49M | 14 | 2026-08-17 |
| Sigilon Therapeutics, Inc. (SGTX) Delisted | Director | 342 | $22.47 | $7.7K | $0 | 5 | 2023-08-11 |
| RGEN | Director | 923 | $166.15 | $153.4K | -$4.07M | 10 | 2020-03-26 |
| Bioverativ Inc. (BIVV) Delisted | Chief Executive Officer | 0 | — | — | $0 | 9 | 2018-03-08 |
| BIIB | EVP Pharmaceutical Oper & Tech | 39,045 | $212.55 | $8.30M | -$10.66M | 36 | 2016-04-05 |
Recent Filings
82 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2026-08-17 | DYN | Sell (S) | −4,986 | -$131.0K | EDGAR |
| 2026-08-13 | DYN | Notice (144) | −4,986 | -$131.0K | EDGAR |
| 2026-06-17 | DYN | Sell (S) | −2,683 | -$49.2K | EDGAR |
| 2026-06-16 | DYN | Notice (144) | −2,683 | -$49.2K | EDGAR |
| 2026-05-14 | DYN | Sell (S) | −3,311 | -$60.8K | EDGAR |
| 2026-05-13 | DYN | Notice (144) | −3,311 | -$60.8K | EDGAR |
| 2026-03-06 | DYN | Sell (S) | −2,732 | -$40.7K | EDGAR |
| 2026-03-05 | DYN | Notice (144) | −2,732 | -$40.7K | EDGAR |
| 2026-02-17 | DYN | Grant (A) | +180,000 | $0 | EDGAR |
| 2025-12-05 | DYN | Notice (144) | −2,662 | -$55.1K | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.