BioAtla's three largest insider shareholders as of September 29, 2026 are Jay M Phd Short (Chief Executive Officer, 52.03K shares), Eric Sievers (Chief Medical Officer, 11.35K shares), Christian Vasquez (Chief Financial Officer, 10.48K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Jay M Phd Short | Chief Executive Officer | 52,035 | 0 | 52,035 | 55.5% | 02 Sep, 2026 |
| 2 | Eric Sievers | Chief Medical Officer | 11,346 | 0 | 11,346 | 12.1% | 02 Sep, 2026 |
| 3 | Christian Vasquez | Chief Financial Officer | 10,476 | 0 | 10,476 | 11.2% | 02 Sep, 2026 |
| 4 | Richard A Waldron | Former Chief Financial Officer | 6,868 | 0 | 6,868 | 7.3% | 02 Mar, 2026 |
| 5 | Scott Andrew Smith | Former President | 6,431 | 0 | 6,431 | 6.9% | 18 Jun, 2025 |
| 6 | Lawrence Steinman | Director | 1,569 | 0 | 1,569 | 1.7% | 18 Jun, 2025 |
| 7 | Mary Ann Gray | Director | 1,548 | 0 | 1,548 | 1.7% | 18 Jun, 2025 |
| 8 | Eddie Williams | Director | 1,204 | 0 | 1,204 | 1.3% | 18 Jun, 2025 |
| 9 | Sylvia Mcbrinn | Director | 1,183 | 0 | 1,183 | 1.3% | 18 Jun, 2025 |
| 10 | Susan Moran | Director | 1,046 | 0 | 1,046 | 1.1% | 18 Jun, 2025 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 31 Aug, 2026 | Christian Vasquez | Chief Financial Officer | Disposed F | 71 | $1.69 | $120 | 10,476 | Direct |
| 31 Aug, 2026 | Jay M Phd Short | Chief Executive Officer | Disposed F | 259 | $1.69 | $438 | 52,035 | Direct |
| 31 Aug, 2026 | Eric Sievers | Chief Medical Officer | Disposed F | 134 | $1.69 | $226 | 11,346 | Direct |
| 11 Mar, 2026 | Jay M Phd Short | Chief Executive Officer | Acquired A | 430,000 | $0.00 | $0 | 53,192 | Direct |
| 10 Mar, 2026 | Eric Sievers | Chief Medical Officer | Acquired A | 240,000 | $0.00 | $0 | 11,974 | Direct |
| 10 Mar, 2026 | Christian Vasquez | Chief Financial Officer | Acquired A | 240,000 | $0.00 | $0 | 10,604 | Direct |
| 28 Feb, 2026 | Jay M Phd Short | Chief Executive Officer | Disposed F | 7,728 | $12.35 | $95.44K | 44,592 | Direct |
| 28 Feb, 2026 | Richard A Waldron | Former Chief Financial Officer | Disposed F | 2,729 | $12.35 | $33.70K | 6,868 | Direct |
| 28 Feb, 2026 | Christian Vasquez | Chief Financial Officer | Disposed F | 1,802 | $12.35 | $22.25K | 5,804 | Direct |
| 28 Feb, 2026 | Eric Sievers | Chief Medical Officer | Disposed F | 3,140 | $12.35 | $38.78K | 7,174 | Direct |
| 30 Nov, 2025 | Richard A Waldron | Chief Financial Officer | Disposed F | 2,371 | $45.20 | $107.17K | 6,923 | Direct |
| 30 Nov, 2025 | Jay M Phd Short | Chief Executive Officer | Disposed F | 6,347 | $45.20 | $286.88K | 44,747 | Direct |
| 30 Nov, 2025 | Eric Sievers | Chief Medical Officer | Disposed F | 2,729 | $45.20 | $123.35K | 7,237 | Direct |
| 30 Nov, 2025 | Christian Vasquez | Officer | Disposed F | 1,566 | $45.20 | $70.78K | 5,840 | Direct |
| 31 Aug, 2025 | Richard A Waldron | Chief Financial Officer | Disposed F | 2,371 | $22.78 | $54.00K | 6,770 | Direct |
| 31 Aug, 2025 | Eric Sievers | Chief Medical Officer | Disposed F | 2,729 | $22.78 | $62.15K | 7,291 | Direct |
| 31 Aug, 2025 | Jay M Phd Short | Chief Executive Officer | Disposed F | 6,347 | $22.78 | $144.55K | 44,874 | Direct |
| 31 Aug, 2025 | Christian Vasquez | Officer | Disposed F | 1,566 | $22.78 | $35.67K | 5,671 | Direct |
| 18 Jun, 2025 | Sylvia Mcbrinn | Director | Acquired A | 23,500 | $0.00 | $0 | 1,183 | Direct |
| 18 Jun, 2025 | Mary Ann Gray | Director | Acquired A | 23,500 | $0.00 | $0 | 1,548 | Direct |