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 |
|---|---|---|---|
| 424B7 | Filing | Dec 23, 2025 | — |
| 424B5 | Prospectus supplement | Jun 11, 2025 | — |
| 424B5 | Prospectus supplement | Jun 10, 2025 | — |
| S-8 | Employee stock plan registration | Aug 28, 2024 | — |
| 424B7 | Filing | Aug 12, 2024 | — |
| S-3ASR | Automatic shelf registration | Aug 12, 2024 | — |
| S-3/A | Filing | Mar 8, 2024 | — |
| 424B5 | Prospectus supplement | Jan 31, 2024 | — |
| 424B5 | Prospectus supplement | Jan 30, 2024 | — |
| S-3 | Shelf registration | Jan 30, 2024 | — |
| 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 | — |
| S-8 | Employee stock plan registration | Aug 10, 2022 | — |
| S-8 | Employee stock plan registration | Aug 10, 2022 | — |
| POS AM | Filing | Jun 2, 2021 | — |
| 424B7 | Filing | May 21, 2021 | — |
| S-3ASR | Automatic shelf registration | Feb 26, 2021 | — |
| 424B5 | Prospectus supplement | Oct 23, 2020 | — |
| 424B5 | Prospectus supplement | Oct 21, 2020 | — |
| S-8 | Employee stock plan registration | Aug 29, 2019 | — |
| S-3 | Shelf registration | Feb 5, 2018 | — |
| S-3 | Shelf registration | Oct 3, 2017 | — |
| 424B5 | Prospectus supplement | May 8, 2017 | — |
| 424B5 | Prospectus supplement | May 4, 2017 | — |
| 424B5 | Prospectus supplement | Jan 27, 2017 | — |
| S-8 | Employee stock plan registration | Sep 28, 2016 | — |
| 424B5 | Prospectus supplement | Apr 24, 2015 | — |
| 424B5 | Prospectus supplement | Apr 23, 2015 | — |
| 424B5 | Prospectus supplement | Nov 7, 2014 | — |
| 424B5 | Prospectus supplement | Nov 7, 2014 | — |
| S-3 | Shelf registration | Sep 19, 2014 | — |
| S-8 | Employee stock plan registration | Aug 8, 2014 | — |
| 424B5 | Prospectus supplement | Nov 18, 2013 | — |
| S-3 | Shelf registration | Sep 13, 2013 | — |
| S-3 | Shelf registration | Nov 6, 2012 | — |
| POS AM | Post-effective amendment no. 2 to form s-1 | Oct 16, 2012 | — |
| S-3 | Shelf registration | Oct 1, 2012 | — |
| S-8 | Employee stock plan registration | Aug 3, 2012 | — |
| 424B3 | Prospectus | Aug 3, 2012 | — |
| 424B3 | Prospectus | Jul 27, 2012 | — |
| 424B5 | Prospectus supplement | Jun 26, 2012 | — |
| 424B5 | Prospectus supplement | Jun 11, 2012 | — |
| POS AM | Post-effective amendment no. 1 to form s-1 | Jun 6, 2012 | — |
| 424B5 | Prospectus supplement | May 11, 2012 | — |
| 424B5 | Prospectus supplement | May 11, 2012 | — |
| S-1 | Registration statement | Apr 13, 2012 | — |
| 424B2 | Prospectus | Nov 12, 2010 | — |
| 424B5 | Prospectus supplement | Nov 9, 2010 | — |
| S-3ASR | Automatic shelf registration | Nov 8, 2010 | — |
| S-8 | Employee stock plan registration | Nov 2, 2010 | — |
Showing 54 filings. 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.