As of September 09, 2026, Harvard Bioscience's top three insider holders are Michael A. Rossi (Chief Financial Officer, 260.54K shares), James W Green (Chief Executive Officer, 245.26K shares), John D Duke (Chief Executive Officer, 180.00K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Michael A. Rossi | Chief Financial Officer | 260,540 | 0 | 260,540 | 23.6% | 03 Jan, 2023 |
| 2 | James W Green | Chief Executive Officer | 245,257 | 0 | 245,257 | 22.2% | 19 Aug, 2025 |
| 3 | John D Duke | Chief Executive Officer | 180,000 | 0 | 180,000 | 16.3% | 23 Mar, 2026 |
| 4 | Kenneth Fletcher Olson | Chief Operating Officer | 155,595 | 0 | 155,595 | 14.1% | 30 Dec, 2021 |
| 5 | Katherine A. Eade | Director | 58,669 | 0 | 58,669 | 5.3% | 12 Jun, 2026 |
| 6 | William Snider | Director | 48,556 | 0 | 48,556 | 4.4% | 11 Jun, 2026 |
| 7 | Mark T Frost | Chief Financial Officer | 47,500 | 0 | 47,500 | 4.3% | 01 Apr, 2026 |
| 8 | Stephen J Denelsky | Director | 37,556 | 0 | 37,556 | 3.4% | 11 Jun, 2026 |
| 9 | Alan I Edrick | Director | 27,391 | 0 | 27,391 | 2.5% | 23 May, 2024 |
| 10 | Jennifer Cote | Chief Financial Officer | 15,902 | 0 | 15,902 | 1.4% | 21 Mar, 2025 |
| 11 | Seth Benjamin Benson | Director | 11,000 | 0 | 11,000 | 1.0% | 25 Jul, 2025 |
| 12 | Robert E. Gagnon | Chief Financial Officer | 11,000 | 0 | 11,000 | 1.0% | 18 Jul, 2025 |
| 13 | Bertrand Loy | Director | 5,658 | 0 | 5,658 | 0.5% | 23 May, 2024 |
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 |
|---|---|---|---|---|---|---|---|---|
| 09 Jun, 2026 | Katherine A. Eade | Director | Acquired A | 16,556 | $0.00 | $0 | 58,669 | Direct |
| 09 Jun, 2026 | Robert E. Gagnon | Director | Acquired A | 16,556 | $0.00 | $0 | 27,556 | Direct |
| 09 Jun, 2026 | Stephen J Denelsky | Director | Acquired A | 16,556 | $0.00 | $0 | 37,556 | Direct |
| 09 Jun, 2026 | William Snider | Director | Acquired A | 16,556 | $0.00 | $0 | 48,556 | Direct |
| 16 Mar, 2026 | Mark T Frost | Chief Financial Officer | Acquired P | 5,000 | $50.00 | $250.00K | 1,750 | Direct |
| 20 Mar, 2026 | Mark T Frost | Chief Financial Officer | Acquired A | 30,000 | $0.00 | $0 | 47,500 | Direct |
| 20 Mar, 2026 | John D Duke | Chief Executive Officer | Acquired A | 75,000 | $0.00 | $0 | 180,000 | Direct |
| 17 Mar, 2026 | Stephen J Denelsky | Director | Acquired P | 10,000 | $4.87 | $48.70K | 21,000 | Direct |
| 16 Mar, 2026 | William Snider | Director | Acquired P | 12,525 | $49.90 | $625.00K | 2,353 | Direct |
| 17 Mar, 2026 | William Snider | Director | Acquired P | 8,475 | $4.85 | $41.10K | 32,000 | Direct |
| 16 Mar, 2026 | John D Duke | Chief Executive Officer | Acquired P | 5,000 | $50.10 | $250.50K | 10,500 | Direct |
| 17 Dec, 2025 | William Snider | Director | Acquired A | 110,000 | $0.00 | $0 | 11,000 | Direct |
| 05 Sep, 2025 | Stephen J Denelsky | Director | Acquired A | 110,000 | $0.00 | $0 | 11,000 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed D | 49,048 | $0.00 | $0 | 279,604 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed F | 33,200 | $5.29 | $175.63K | 276,284 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed D | 119,332 | $0.00 | $0 | 264,351 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed F | 11,540 | $5.29 | $61.05K | 263,197 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed D | 66,036 | $0.00 | $0 | 256,591 | Direct |
| 15 Aug, 2025 | James W Green | Director | Disposed D | 113,366 | $0.00 | $0 | 245,257 | Direct |
| 08 Aug, 2025 | John D Duke | Chief Executive Officer | Acquired A | 500,000 | $0.00 | $0 | 50,000 | Direct |