As of November 6, 2026, American Superconductor Corp has Schedule 13D or 13G filings on record, none whose latest reports a stake of 5% or more. 4 filings are on record since January 30, 2026 (Schedule 13G/A, July 31, 2026).
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Key facts
- · Reporting person: Vanguard Capital Management · Sole voting: 356,206 · Shared voting: 0 · Sole dispositive: 2,390,425 · Shared dispositive: 0 · SCHEDULE 13G/A, 2026-07-31
- · Holder: Vanguard Capital Management · Percent: 5% · SCHEDULE 13G
- · Holder: The Vanguard Group · Percent: 0% · SCHEDULE 13G/A
- · Holder: The Vanguard Group · Percent: 7.4% · SCHEDULE 13G/A
American Superconductor Corp has 4 Schedule 13D or 13G filings on record since 2026-01-30. No holder's latest filing reports 5% or more. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Vanguard Capital Management | 4.93% | 2,390,425 | SCHEDULE 13G/A, 2026-07-31 | 2026-06-30 |
| The Vanguard Group | 0% | 0 | SCHEDULE 13G/A, 2026-03-26 | 2026-03-13 |
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More on American Superconductor Corp and the records around it.
American Superconductor Corp elsewhere on the record
Companies that share a holder
- Vanguard Capital Management also filed stake reports on 1495 other companies: A10 Networks Inc (Oct 2026), Altisource Portfolio Solutions SA (Oct 2026), Alto Neuroscience Inc (Oct 2026)
- The Vanguard Group also filed stake reports on 2384 other companies: BellRing Brands, Inc. (Sep 2026), CAL-MAINE FOODS INC (Sep 2026), FTAI Aviation Ltd. (Sep 2026)
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Voting and dispositive power, as filed
| Reporting person | Sole voting | Shared voting | Sole dispositive | Shared dispositive | Filing |
|---|---|---|---|---|---|
| Vanguard Capital Management | 356,206 | 0 | 2,390,425 | 0 | SCHEDULE 13G/A, 2026-07-31 |
The latest filing identifies American Superconductor Corp by CUSIP 030111207 and gives its principal executive office as 114 East Main Street, Ayer, MA 01432 (SCHEDULE 13G/A, 2026-07-31).
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2026-01-30 | The Vanguard Group | 7.4% | SCHEDULE 13G/A |
| 2026-03-26 | The Vanguard Group | 0% | SCHEDULE 13G/A |
| 2026-04-29 | Vanguard Capital Management | 5% | SCHEDULE 13G |
| 2026-07-31 | Vanguard Capital Management | 4.93% | SCHEDULE 13G/A |
Also on the record for American Superconductor Corp
| Date | Record | Figure | Our page | Source |
|---|---|---|---|---|
| September 21, 2026 | Leadership change filing (Form 8-K, Item 5.02) | — | Leadership changes | Source |
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Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.