As of September 09, 2026, the three largest insider holders of AMSC are Daniel P Mcgahn (Chairman, President And Ceo, 1.13Mn shares), John W Jr Kosiba (Svp, Cfo Treasurer, 352.89K shares), John W Jr Kosiba (Svp, Cfo Treasurer, 334.38K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Daniel P Mcgahn | Chairman, President And Ceo | 1,131,929 | 0 | 1,131,929 | 66.0% | 11 Jun, 2026 |
| 2 | John W Jr Kosiba | Svp, Cfo Treasurer | 334,377 | 0 | 334,377 | 19.5% | 11 Jun, 2026 |
| 3 | David R Jr Oliver | Director | 63,823 | 0 | 63,823 | 3.7% | 07 Apr, 2026 |
| 4 | Vikram S Budhraja | Director | 59,299 | 0 | 59,299 | 3.5% | 13 Jun, 2022 |
| 5 | Arthur H House | Director | 51,779 | 0 | 51,779 | 3.0% | 07 Apr, 2026 |
| 6 | Barbara G. Littlefield | Director | 35,427 | 0 | 35,427 | 2.1% | 07 Apr, 2026 |
| 7 | Margaret D. Klein | Director | 19,492 | 0 | 19,492 | 1.1% | 07 Apr, 2026 |
| 8 | Laura A. Dambier | Director | 14,992 | 0 | 14,992 | 0.9% | 12 Jun, 2026 |
| 9 | Terence Robert Donnelly | Director | 2,665 | 0 | 2,665 | 0.2% | 07 Apr, 2026 |
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 |
|---|---|---|---|---|---|---|---|---|
| 11 Jun, 2026 | Laura A. Dambier | Director | Disposed S | 4,000 | $37.63 | $150.52K | 14,992 | Direct |
| 11 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 5,026 | $37.33 | $187.60K | 336,120 | Direct |
| 11 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 11,508 | $37.28 | $429.05K | 1,136,538 | Direct |
| 11 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 4,609 | $37.85 | $174.46K | 1,131,929 | Direct |
| 11 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 1,743 | $37.85 | $65.98K | 334,377 | Direct |
| 08 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 3,286 | $41.50 | $136.37K | 342,695 | Direct |
| 08 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 4,992 | $41.39 | $206.61K | 1,152,724 | Direct |
| 08 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 1,549 | $42.35 | $65.60K | 341,146 | Direct |
| 08 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 4,678 | $42.19 | $197.38K | 1,148,046 | Direct |
| 01 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Acquired A | 30,000 | $0.00 | $0 | 382,890 | Direct |
| 01 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Acquired A | 60,000 | $0.00 | $0 | 1,243,134 | Direct |
| 02 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 5,704 | $49.46 | $282.13K | 377,186 | Direct |
| 02 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 13,762 | $49.45 | $680.54K | 1,229,372 | Direct |
| 02 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 27,900 | $50.63 | $1.41Mn | 1,201,472 | Direct |
| 02 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 12,122 | $50.62 | $613.60K | 365,064 | Direct |
| 02 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 28,558 | $51.46 | $1.47Mn | 1,172,914 | Direct |
| 02 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 12,036 | $51.47 | $619.44K | 353,028 | Direct |
| 02 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 600 | $52.19 | $31.32K | 352,428 | Direct |
| 02 Jun, 2026 | Daniel P Mcgahn | Chairman, President And Ceo | Disposed S | 2,305 | $52.14 | $120.17K | 1,170,609 | Direct |
| 03 Jun, 2026 | John W Jr Kosiba | Svp, Cfo Treasurer | Disposed S | 3,200 | $48.31 | $154.58K | 349,228 | Direct |