Welcome to our dedicated page for American Superconductor SEC filings (Ticker: AMSC), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
American Superconductor Corp. filings document the company’s operating results, material events, acquisition accounting, governance matters and common-stockholder votes. Recent Form 8-K reports include Item 2.02 disclosures for quarterly financial results and related press-release exhibits, showing how AMSC reports revenue, profitability, outlook and financial condition to the market.
The filing record also includes acquisition-related 8-K/A disclosure for Comtrafo, with audited and interim financial statements and unaudited pro forma condensed consolidated financial information. Governance filings cover annual meeting results, including director elections, auditor ratification and advisory executive-compensation voting, reflecting formal stockholder oversight of the company’s board and public-company reporting structure.
American Superconductor Corporation reports a year of profitable growth driven by grid, industrial and naval power solutions and two acquisitions. It bought Brazil-based transformer maker Comtrafo in December 2025 and U.S. power conversion group Megatran/NWL in August 2024, expanding its Grid segment.
The company estimates an annual addressable market of over $15 billion, supported by $2.3 trillion of 2025 global energy-transition investment and rising U.S. defense and shipbuilding spending. International sales are significant, with 52% of fiscal 2025 revenue coming from outside the United States and notable customer concentration with Inox in its Wind segment.
AMSC ended March 31, 2026 with $147.6 million in cash, cash equivalents and restricted cash and generated $23.1 million of operating cash flow. It released a $118.4 million deferred tax valuation allowance after achieving profitability but disclosed a material weakness in controls over acquisition accounting, which management is working to remediate.
American Superconductor (AMSC) reported strong growth for the fourth quarter and fiscal year ended March 31, 2026. Fourth-quarter revenue rose to $86.4 million from $66.7 million, with GAAP net income increasing to $4.5 million, or $0.10 per share. Non-GAAP net income for the quarter climbed to $14.1 million, or $0.31 per share.
For fiscal 2025, revenue grew 34% year over year to a recent record of $299.2 million, driven by higher Grid and Wind sales and contributions from the Comtrafo acquisition. Full-year GAAP net income was $133.8 million, or $3.12 per share, largely reflecting a substantial non-cash tax benefit from releasing most of the valuation allowance on deferred tax assets. Full-year non-GAAP net income rose to $158.1 million, or $3.68 per share.
AMSC ended March 31, 2026 with $147.6 million in cash, cash equivalents and restricted cash and a 12‑month backlog of approximately $280 million, nearly 40% higher year over year. For the quarter ending June 30, 2026, the company expects revenue to exceed $85 million, GAAP net income to exceed $3.0 million, and non-GAAP net income to exceed $8.0 million, or $0.17 per share.
American Superconductor Corp disclosure: Vanguard Capital Management reports beneficial ownership of 2,384,736 shares of Common Stock, representing 5% of the class. The filing states Vanguard has sole dispositive power over 2,384,736 shares and sole voting power over 345,268 shares. The statement identifies affiliated Vanguard entities that exercise dispositive or voting power on behalf of funds and managed accounts. The filing is signed by a Vanguard officer on 04/29/2026.
Donnelly Terence Robert reported acquisition or exercise transactions in this Form 4 filing.
American Superconductor Corporation director Terence Robert Donnelly received an equity award of company stock. On April 3, 2026, he was granted 2,665 shares of common stock at no cash cost as an immediately vested award under the company’s Amended and Restated 2007 Director Stock Plan. Following this grant, he directly holds 2,665 shares of American Superconductor common stock.
OLIVER DAVID R JR reported acquisition or exercise transactions in this Form 4 filing.
American Superconductor director David R. Oliver Jr. received a grant of 3,116 shares of Common Stock on April 3, 2026. The shares were awarded at a price of $0.00 per share, reflecting a stock-based compensation grant rather than a market purchase.
According to the footnotes, this award consisted of immediately vested shares made under the company’s Amended and Restated 2007 Director Stock Plan. Following this grant, Oliver directly holds 63,823 shares of American Superconductor common stock.
Littlefield Barbara G. reported acquisition or exercise transactions in this Form 4 filing.
American Superconductor (AMSC) director Barbara G. Littlefield received a grant of 3,116 shares of common stock as compensation. The shares were immediately vested and were awarded under the company’s Amended and Restated 2007 Director Stock Plan, as amended. Following this grant, she directly holds 35,427 shares of AMSC common stock.
Klein Margaret D. reported acquisition or exercise transactions in this Form 4 filing.
AMERICAN SUPERCONDUCTOR CORP director Margaret D. Klein received a grant of 3,116 shares of common stock on April 3, 2026 at $0.00 per share. The award vested immediately and was made under the company’s Amended and Restated 2007 Director Stock Plan.
After this compensation grant, she holds 19,492 shares of common stock directly. This is not an open-market purchase or sale but a stock-based director compensation award.
House Arthur H reported acquisition or exercise transactions in this Form 4 filing.
AMERICAN SUPERCONDUCTOR CORP director Arthur H. House received a stock grant of 3,116 common shares as compensation. The award consisted of immediately vested shares issued at no cash cost to him under the company’s Amended and Restated 2007 Director Stock Plan. Following this grant, he directly holds 51,779 shares of AMERICAN SUPERCONDUCTOR common stock.
Dambier Laura A. reported acquisition or exercise transactions in this Form 4 filing.
American Superconductor (AMSC) director Laura A. Dambier received an equity grant of 3,116 shares of common stock. The shares were awarded at no cash cost to her and vested immediately under the company’s Amended and Restated 2007 Director Stock Plan.
After this grant, she directly holds 18,992 American Superconductor common shares, reflecting routine stock-based compensation for board service rather than an open-market purchase or sale.
The Vanguard Group filed an amendment reporting 0% beneficial ownership of American Superconductor Corp common stock. The filing states that, on January 12, 2026, certain Vanguard subsidiaries were disaggregated for reporting in accordance with SEC Release No. 34-39538 (January 12, 1998), and those entities now report separately.
The amendment lists amount beneficially owned: 0 and percent of class: 0%. The filing is signed by Vanguard's Head of Global Fund Administration on 03/26/2026.