As of June 02, 2026, the three largest insider holders of AMSC are Daniel P Mcgahn (Chairman, President And Ceo, 1.18Mn shares), John W Jr Kosiba (Svp, Cfo Treasurer, 352.89K shares), David R Jr Oliver (Director, 63.82K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Vikram S Budhraja | - | 59,299 | 0 | 13 Jun, 2022 |
| David R Jr Oliver | - | 63,823 | 0 | 07 Apr, 2026 |
| Daniel P Mcgahn | Chairman, President And Ceo | 1,183,134 | 0 | 06 Aug, 2025 |
| Arthur H House | - | 51,779 | 0 | 07 Apr, 2026 |
| John W Jr Kosiba | Svp, Cfo Treasurer | 352,890 | 0 | 06 Aug, 2025 |
| Barbara G. Littlefield | - | 35,427 | 0 | 07 Apr, 2026 |
| Laura A. Dambier | - | 18,992 | 0 | 07 Apr, 2026 |
| Margaret D. Klein | - | 19,492 | 0 | 07 Apr, 2026 |
| Terence Robert Donnelly | - | 2,665 | 0 | 07 Apr, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 03 Apr, 2026 | Barbara G. Littlefield | Common Stock | A | 3,116 | $0.00 | 35,427 | D | A |
| 03 Apr, 2026 | Barbara G. Littlefield | Common Stock | A | 3,116 | $0.00 | 35,427 | D | A |
| 03 Apr, 2026 | Arthur H House | Common Stock | A | 3,116 | $0.00 | 51,779 | D | A |
| 03 Apr, 2026 | Laura A. Dambier | Common Stock | A | 3,116 | $0.00 | 18,992 | D | A |
| 03 Apr, 2026 | Terence Robert Donnelly | Common Stock | A | 2,665 | $0.00 | 2,665 | D | A |
| 03 Apr, 2026 | David R Jr Oliver | Common Stock | A | 3,116 | $0.00 | 63,823 | D | A |
| 03 Apr, 2026 | Margaret D. Klein | Common Stock | A | 3,116 | $0.00 | 19,492 | D | A |
| 03 Apr, 2026 | Margaret D. Klein | Common Stock | A | 3,116 | $0.00 | 19,492 | D | A |
| 24 Feb, 2026 | David R Jr Oliver | Common Stock | D | 200 | $34.10 | 60,707 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 73,105 | $54.26 | 1,210,877 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 73,105 | $54.26 | 1,210,877 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 73,105 | $54.26 | 1,210,877 | D | S |
| 04 Aug, 2025 | John W Jr Kosiba | Common Stock | D | 34,260 | $54.34 | 368,630 | D | S |
| 04 Aug, 2025 | John W Jr Kosiba | Common Stock | D | 34,260 | $54.34 | 368,630 | D | S |
| 04 Aug, 2025 | John W Jr Kosiba | Common Stock | D | 34,260 | $54.34 | 368,630 | D | S |
| 04 Aug, 2025 | John W Jr Kosiba | Common Stock | D | 15,740 | $55.13 | 352,890 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 27,743 | $55.11 | 1,183,134 | D | S |
| 04 Aug, 2025 | John W Jr Kosiba | Common Stock | D | 15,740 | $55.13 | 352,890 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 27,743 | $55.11 | 1,183,134 | D | S |
| 04 Aug, 2025 | Daniel P Mcgahn | Common Stock | D | 27,743 | $55.11 | 1,183,134 | D | S |