American Superconductor Corp /DE/ SEC filings AMSC
American Superconductor Corp /DE/ has 1,003 filings in SEC EDGAR's recent list, going back to Jan 31, 2008. Its latest annual report, Form ARS, was filed on Jun 18, 2026 for the period ended Mar 31, 2026. The latest quarterly report (Form 10-Q) was filed on Nov 4, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Nov 4, 2026 (results of operations). The company's fiscal year ends on March 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 10-Q | Quarterly report | Nov 4, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Results of operations
|
Nov 4, 2026 | Nov 4, 2026 |
| 8-K |
Current report
Officer or director change
|
Sep 21, 2026 | Sep 17, 2026 |
| 10-Q | Quarterly report | Aug 5, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations, Shareholder vote results
|
Aug 5, 2026 | Jul 31, 2026 |
| ARS | Annual report to shareholders | Jun 18, 2026 | Mar 31, 2026 |
| DEFA14A | Additional proxy material | Jun 18, 2026 | — |
| DEF 14A | Proxy statement | Jun 18, 2026 | Jul 31, 2026 |
| 8-K |
Current report
Officer or director change
|
Jun 2, 2026 | Jun 1, 2026 |
| SD | Specialized disclosure (conflict minerals) | May 29, 2026 | — |
| 10-K | Annual report | May 27, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations
|
May 27, 2026 | May 27, 2026 |
| 8-K/A | Amended current report | Feb 17, 2026 | Dec 5, 2025 |
| 10-Q | Quarterly report | Feb 4, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Feb 4, 2026 | Feb 4, 2026 |
| 8-K |
Current report
Other events
|
Dec 23, 2025 | Dec 23, 2025 |
| 424B7 | Filing | Dec 23, 2025 | — |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Unregistered share sale, Other events
|
Dec 10, 2025 | Dec 5, 2025 |
| 10-Q | Quarterly report | Nov 5, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 5, 2025 | Nov 5, 2025 |
| 10-Q | Quarterly report | Jul 30, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Jul 30, 2025 | Jul 30, 2025 |
| 8-K |
Current report
Shareholder vote results
|
Jul 29, 2025 | Jul 25, 2025 |
| ARS | Annual report to shareholders | Jun 13, 2025 | Mar 31, 2025 |
| DEFA14A | Additional proxy material | Jun 13, 2025 | — |
| DEF 14A | Proxy statement | Jun 13, 2025 | Jul 25, 2025 |
| 8-K |
Current report
Other events
|
Jun 11, 2025 | Jun 10, 2025 |
| 424B5 | Prospectus supplement | Jun 11, 2025 | — |
| 424B5 | Prospectus supplement | Jun 10, 2025 | — |
| SD | Specialized disclosure (conflict minerals) | May 21, 2025 | — |
| 10-K | Annual report | May 21, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations, Officer or director change
|
May 21, 2025 | May 15, 2025 |
| 8-K |
Current report
Results of operations, Bylaw or fiscal year change
|
Feb 5, 2025 | Jan 30, 2025 |
| 10-Q | Quarterly report | Feb 5, 2025 | Dec 31, 2024 |
| 10-Q | Quarterly report | Oct 30, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations
|
Oct 30, 2024 | Oct 30, 2024 |
| S-8 | Employee stock plan registration | Aug 28, 2024 | — |
| 8-K |
Current report
Other events
|
Aug 13, 2024 | Aug 12, 2024 |
| 424B7 | Filing | Aug 12, 2024 | — |
| S-3ASR | Automatic shelf registration | Aug 12, 2024 | — |
| 8-K/A | Amended current report | Aug 6, 2024 | Aug 1, 2024 |
| 10-Q | Quarterly report | Aug 6, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations
|
Aug 6, 2024 | Aug 6, 2024 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Aug 5, 2024 | Aug 2, 2024 |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Other events
|
Aug 5, 2024 | Aug 1, 2024 |
| ARS | Annual report to shareholders | Jun 20, 2024 | Mar 31, 2024 |
| DEFA14A | Additional proxy material | Jun 20, 2024 | — |
| DEF 14A | Proxy statement | Jun 20, 2024 | Aug 2, 2024 |
| PRE 14A | Preliminary proxy statement | Jun 10, 2024 | Aug 2, 2024 |
| 10-K | Annual report | May 29, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations, Officer or director change
|
May 29, 2024 | May 23, 2024 |
| SD | Specialized disclosure (conflict minerals) | May 28, 2024 | — |
| EFFECT | Filing | Mar 15, 2024 | — |
| CORRESP | Letter to the SEC | Mar 13, 2024 | — |
| S-3/A | Filing | Mar 8, 2024 | — |
| CORRESP | Letter to the SEC | Mar 6, 2024 | — |
| CORRESP | Letter to the SEC | Mar 5, 2024 | — |
| UPLOAD | Letter from the SEC | Feb 5, 2024 | — |
| 424B5 | Prospectus supplement | Jan 31, 2024 | — |
| 8-K |
Current report
Other events
|
Jan 31, 2024 | Jan 30, 2024 |
| 424B5 | Prospectus supplement | Jan 30, 2024 | — |
| S-3 | Shelf registration | Jan 30, 2024 | — |
| 10-Q | Quarterly report | Jan 24, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Results of operations
|
Jan 24, 2024 | Jan 24, 2024 |
| 10-Q | Quarterly report | Nov 1, 2023 | Sep 30, 2023 |
| 8-K |
Current report
Results of operations
|
Nov 1, 2023 | Nov 1, 2023 |
| 8-K |
Current report
Shareholder vote results
|
Aug 11, 2023 | Aug 11, 2023 |
| 10-Q | Quarterly report | Aug 9, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Results of operations
|
Aug 9, 2023 | Aug 9, 2023 |
| ARS | Annual report to shareholders | Jun 28, 2023 | Dec 31, 2022 |
| DEFA14A | Additional proxy material | Jun 28, 2023 | — |
| DEF 14A | Proxy statement | Jun 28, 2023 | Aug 11, 2023 |
| 8-K |
Current report
Officer or director change
|
Jun 21, 2023 | Jun 15, 2023 |
| 10-K | Annual report | May 31, 2023 | Mar 31, 2023 |
| 8-K |
Current report
Results of operations
|
May 31, 2023 | May 31, 2023 |
| SD | Specialized disclosure (conflict minerals) | May 31, 2023 | — |
| 10-Q | Quarterly report | Feb 1, 2023 | Dec 31, 2022 |
| 8-K |
Current report
Results of operations
|
Feb 1, 2023 | Feb 1, 2023 |
| S-8 POS | Filing | Nov 17, 2022 | — |
| S-8 POS | Filing | Nov 17, 2022 | — |
| S-8 POS | Filing | Nov 17, 2022 | — |
| S-8 POS | Filing | Nov 17, 2022 | — |
| S-8 POS | Filing | Nov 17, 2022 | — |
| S-8 POS | Filing | Nov 17, 2022 | — |
| 10-Q | Quarterly report | Nov 1, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Results of operations
|
Nov 1, 2022 | Nov 1, 2022 |
| S-8 | Employee stock plan registration | Aug 10, 2022 | — |
| S-8 | Employee stock plan registration | Aug 10, 2022 | — |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Aug 5, 2022 | Aug 2, 2022 |
| 10-Q | Quarterly report | Aug 3, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Results of operations
|
Aug 3, 2022 | Aug 3, 2022 |
| DEFA14A | Additional proxy material | Jul 26, 2022 | — |
| DEFA14A | Additional proxy material | Jun 23, 2022 | — |
| DEF 14A | Proxy statement | Jun 23, 2022 | Aug 2, 2022 |
| 8-K |
Current report
Officer or director change
|
Jun 10, 2022 | Jun 7, 2022 |
| 10-K | Annual report | Jun 1, 2022 | Mar 31, 2022 |
| 8-K |
Current report
Results of operations
|
Jun 1, 2022 | Jun 1, 2022 |
| SD | Specialized disclosure (conflict minerals) | May 23, 2022 | — |
| 10-Q | Quarterly report | Feb 2, 2022 | Dec 31, 2021 |
| 8-K |
Current report
Results of operations
|
Feb 2, 2022 | Feb 2, 2022 |
| 10-Q | Quarterly report | Nov 8, 2021 | Sep 30, 2021 |
| 8-K |
Current report
Results of operations
|
Nov 8, 2021 | Nov 8, 2021 |
| 10-Q | Quarterly report | Aug 4, 2021 | Jun 30, 2021 |
| 8-K |
Current report
Results of operations
|
Aug 4, 2021 | Aug 4, 2021 |
| 8-K |
Current report
Shareholder vote results
|
Aug 2, 2021 | Jul 30, 2021 |
| EFFECT | Filing | Jun 21, 2021 | — |
| DEFA14A | Additional proxy material | Jun 17, 2021 | — |
| DEF 14A | Proxy statement | Jun 17, 2021 | Jul 30, 2021 |
| POS AM | Filing | Jun 2, 2021 | — |
| 10-K | Annual report | Jun 2, 2021 | Mar 31, 2021 |
| 8-K |
Current report
Results of operations
|
Jun 2, 2021 | Jun 2, 2021 |
| POSASR | Filing | Jun 2, 2021 | — |
| SD | Specialized disclosure (conflict minerals) | May 27, 2021 | — |
| 8-K |
Current report
Officer or director change
|
May 25, 2021 | May 20, 2021 |
| 8-K |
Current report
Other events
|
May 21, 2021 | May 21, 2021 |
| 424B7 | Filing | May 21, 2021 | — |
| 8-K |
Current report
Material agreement
|
May 10, 2021 | May 6, 2021 |
| S-3ASR | Automatic shelf registration | Feb 26, 2021 | — |
| 8-K |
Current report
Other events
|
Feb 26, 2021 | Feb 26, 2021 |
| 10-Q | Quarterly report | Feb 3, 2021 | Dec 31, 2020 |
| 8-K |
Current report
Results of operations
|
Feb 3, 2021 | Feb 3, 2021 |
| 8-K |
Current report
Bylaw or fiscal year change
|
Feb 1, 2021 | Jan 28, 2021 |
| 8-K/A | Amended current report | Dec 14, 2020 | Oct 1, 2020 |
| 10-Q | Quarterly report | Nov 4, 2020 | Sep 30, 2020 |
| 8-K |
Current report
Results of operations
|
Nov 4, 2020 | Nov 4, 2020 |
| 8-K |
Current report
Other events
|
Oct 26, 2020 | Oct 22, 2020 |
| 424B5 | Prospectus supplement | Oct 23, 2020 | — |
| 424B5 | Prospectus supplement | Oct 21, 2020 | — |
| 8-K |
Current report
Results of operations
|
Oct 5, 2020 | Oct 5, 2020 |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Unregistered share sale
|
Oct 5, 2020 | Oct 1, 2020 |
| 8-K |
Current report
Other events
|
Oct 2, 2020 | Oct 1, 2020 |
| 8-K |
Current report
Other events
|
Sep 16, 2020 | Sep 11, 2020 |
| 10-Q | Quarterly report | Aug 5, 2020 | Jun 30, 2020 |
| 8-K |
Current report
Results of operations, Shareholder vote results
|
Aug 5, 2020 | Jul 31, 2020 |
| DEFA14A | Additional proxy material | Jun 19, 2020 | — |
| DEF 14A | Proxy statement | Jun 19, 2020 | Jul 31, 2020 |
| 10-K | Annual report | Jun 2, 2020 | Mar 31, 2020 |
| 8-K |
Current report
Results of operations
|
Jun 2, 2020 | Jun 2, 2020 |
| 8-K |
Current report
Officer or director change
|
May 27, 2020 | May 21, 2020 |
| SD | Specialized disclosure (conflict minerals) | May 26, 2020 | — |
| 10-Q | Quarterly report | Feb 5, 2020 | Dec 31, 2019 |
| 8-K |
Current report
Results of operations
|
Feb 5, 2020 | Feb 5, 2020 |
| 10-Q | Quarterly report | Nov 5, 2019 | Sep 30, 2019 |
| 8-K |
Current report
Results of operations
|
Nov 5, 2019 | Nov 5, 2019 |
| S-8 | Employee stock plan registration | Aug 29, 2019 | — |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Aug 6, 2019 | Aug 1, 2019 |
| 10-Q | Quarterly report | Aug 6, 2019 | Jun 30, 2019 |
| 8-K |
Current report
Results of operations
|
Aug 6, 2019 | Aug 6, 2019 |
| DEFA14A | Additional proxy material | Jun 20, 2019 | — |
| DEF 14A | Proxy statement | Jun 20, 2019 | Aug 1, 2019 |
| 10-K | Annual report | Jun 5, 2019 | Mar 31, 2019 |
| 8-K |
Current report
Results of operations, Officer or director change
|
Jun 5, 2019 | Jun 1, 2019 |
| SD | Specialized disclosure (conflict minerals) | May 30, 2019 | — |
| CT ORDER | Filing | May 30, 2019 | — |
| 8-K |
Current report
Officer or director change
|
May 24, 2019 | May 21, 2019 |
| CT ORDER | Filing | Feb 13, 2019 | — |
| 10-Q | Quarterly report | Feb 5, 2019 | Dec 31, 2018 |
| 8-K |
Current report
Results of operations, Other events
|
Feb 5, 2019 | Feb 5, 2019 |
| 10-Q | Quarterly report | Nov 6, 2018 | Sep 30, 2018 |
| 8-K |
Current report
Results of operations
|
Nov 6, 2018 | Nov 6, 2018 |
| 8-K |
Current report
Material agreement
|
Oct 31, 2018 | Oct 31, 2018 |
| CT ORDER | Filing | Aug 30, 2018 | — |
| CT ORDER | Filing | Aug 10, 2018 | — |
| CT ORDER | Filing | Aug 10, 2018 | — |
| 8-K |
Current report
Shareholder vote results
|
Aug 1, 2018 | Jul 27, 2018 |
| 10-Q | Quarterly report | Jul 31, 2018 | Jun 30, 2018 |
| 8-K |
Current report
Results of operations
|
Jul 31, 2018 | Jul 31, 2018 |
| CT ORDER | Filing | Jul 13, 2018 | — |
| 8-K |
Current report
Material agreement
|
Jul 9, 2018 | Jul 3, 2018 |
| 8-K |
Current report
Officer or director change
|
Jul 3, 2018 | Jun 28, 2018 |
| DEFA14A | Additional proxy material | Jun 15, 2018 | — |
| DEF 14A | Proxy statement | Jun 15, 2018 | Jul 27, 2018 |
| 8-K |
Current report
Officer or director change
|
Jun 14, 2018 | Jun 14, 2018 |
| 10-K/A | Amended annual report | Jun 7, 2018 | Jun 7, 2018 |
| 10-K | Annual report | Jun 6, 2018 | Mar 31, 2018 |
| 8-K |
Current report
Results of operations
|
Jun 6, 2018 | Jun 6, 2018 |
| SD | Specialized disclosure (conflict minerals) | May 25, 2018 | — |
| 8-K |
Current report
Officer or director change
|
Apr 10, 2018 | Apr 10, 2018 |
| 8-K |
Current report
Acquisition or sale of assets
|
Apr 3, 2018 | Mar 28, 2018 |
| EFFECT | Filing | Feb 15, 2018 | — |
| UPLOAD | Letter from the SEC | Feb 13, 2018 | — |
| CORRESP | Letter to the SEC | Feb 13, 2018 | — |
| S-3 | Shelf registration | Feb 5, 2018 | — |
| 10-Q | Quarterly report | Feb 5, 2018 | Dec 31, 2017 |
| 8-K |
Current report
Results of operations
|
Feb 5, 2018 | Feb 5, 2018 |
| 8-K |
Current report
Material agreement
|
Feb 1, 2018 | Feb 1, 2018 |
| 10-Q | Quarterly report | Nov 7, 2017 | Sep 30, 2017 |
| 8-K |
Current report
Results of operations
|
Nov 7, 2017 | Nov 7, 2017 |
| EFFECT | Filing | Oct 23, 2017 | — |
| CORRESP | Letter to the SEC | Oct 17, 2017 | — |
| UPLOAD | Letter from the SEC | Oct 11, 2017 | — |
| S-3 | Shelf registration | Oct 3, 2017 | — |
| 8-K |
Current report
Unregistered share sale, Other events
|
Sep 26, 2017 | Sep 25, 2017 |
| CT ORDER | Filing | Sep 11, 2017 | — |
| 10-Q | Quarterly report | Aug 8, 2017 | Jun 30, 2017 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2017 | Aug 8, 2017 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Aug 1, 2017 | Jul 27, 2017 |
| CT ORDER | Filing | Jul 10, 2017 | — |
| 8-K |
Current report
Officer or director change
|
Jul 3, 2017 | Jun 28, 2017 |
| DEFA14A | Additional proxy material | Jun 16, 2017 | — |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Motors & Generators (SIC 3621)
- Listed as
- AMSC (Nasdaq)
- Fiscal year ends
- March 31
- Incorporated in
- DE
- Headquarters
- Devens, MA
- SEC filer status
- Large accelerated filer
- SEC CIK
- 880807
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.