American Superconductor Corporation (AMSC) Ownership
AMSC ownership summary
as of October 18, 2026- Institutions
- 75.0% of shares outstanding
- Insiders
- 3.45% of shares outstanding
- Shares outstanding
- 48.4M
- Float
- 46.8M shares available to trade
- Short interest
- 8.34% 3.9M shares short
- Days to cover
- 5.54 short interest down 0.9% vs prior month
- Institutions 75.03%
- Insiders 3.45%
- Other investors 21.53%
AMSC top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 8.45% | 4.1M | $105.1M | +112,721 (+2.8%) | June 30, 2026 |
| 2 | Vanguard Capital Management, LLC | 4.20% | 2.0M | $52.2M | −5,249 (−0.3%) | June 30, 2026 |
| 3 | Barrow Hanley Mewhinney & Strauss LLC | 3.52% | 1.7M | $43.7M | +564,213 (+49.5%) | June 30, 2026 |
| 4 | UBS Group AG | 2.95% | 1.4M | $36.7M | +829,269 (+138.3%) | June 30, 2026 |
| 5 | Vanguard Portfolio Management, LLC | 2.93% | 1.4M | $36.4M | −292,814 (−17.1%) | June 30, 2026 |
| 6 | State Street Corp | 2.80% | 1.4M | $34.9M | +97,154 (+7.7%) | June 30, 2026 |
| 7 | The Goldman Sachs Group Inc | 2.67% | 1.3M | $33.2M | +584,543 (+82.4%) | June 30, 2026 |
| 8 | Geode Capital Management, LLC | 2.57% | 1.2M | $31.9M | +74,046 (+6.3%) | June 30, 2026 |
| 9 | First Trust Advisors L.P. | 2.41% | 1.2M | $30.0M | +390,156 (+50.1%) | June 30, 2026 |
| 10 | Oberweis Asset Management Inc | 2.04% | 988K | $25.3M | +137,600 (+16.2%) | June 30, 2026 |
| 11 | Awm Investment Company Inc | 1.96% | 952K | $24.4M | +150,000 (+18.7%) | June 30, 2026 |
| 12 | Baillie Gifford & Co Limited. | 1.93% | 933K | $24.0M | −514,111 (−35.5%) | June 30, 2026 |
| 13 | Emerald Advisers, LLC | 1.74% | 844K | $21.7M | +86,552 (+11.4%) | June 30, 2026 |
| 14 | Legal & General Group PLC | 1.56% | 757K | $19.4M | +226,732 (+42.8%) | June 30, 2026 |
| 15 | Dimensional Fund Advisors, Inc. | 1.33% | 646K | $16.6M | −12,306 (−1.9%) | June 30, 2026 |
| 16 | Morgan Stanley - Brokerage Accounts | 1.31% | 636K | $16.3M | +1,992 (+0.3%) | June 30, 2026 |
| 17 | Nuveen, LLC | 1.30% | 628K | $16.1M | −392,541 (−38.4%) | June 30, 2026 |
| 18 | Telemark Asset Management, LLC | 1.24% | 600K | $15.4M | — | June 30, 2026 |
| 19 | Royce & Associates, LP | 1.15% | 556K | $14.3M | +13,043 (+2.4%) | June 30, 2026 |
| 20 | Emerald Mutual Fund Advisers Trust | 1.11% | 539K | $13.8M | +100,080 (+22.8%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 14 holders added 3.4M shares and 5 cut 1.2M.
AMSC top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.98% | 1.4M | $37.0M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.54% | 1.2M | $31.5M | −14,144 (−1.1%) | September 30, 2026 |
| 3 | Oberweis Micro-Cap | 1.91% | 925K | $23.8M | +140,100 (+17.8%) | June 30, 2026 |
| 4 | First Trust NASDAQ® Cln Edge®StGidIfsETF | 1.37% | 665K | $17.1M | — | September 30, 2026 |
| 5 | Fidelity Small Cap Index | 1.07% | 516K | $13.2M | +4,619 (+0.9%) | July 31, 2026 |
| 6 | American Beacon Small Cp Val R5 | 1.02% | 495K | $12.7M | — | August 31, 2026 |
| 7 | Edinburgh Worldwide Ord | 0.93% | 453K | $11.6M | — | June 30, 2026 |
| 8 | iShares Russell 2000 Growth ETF | 0.93% | 449K | $11.5M | −568 (−0.1%) | September 30, 2026 |
| 9 | Vanguard Strategic Equity Inv | 0.86% | 418K | $10.7M | −52,570 (−11.2%) | June 30, 2026 |
| 10 | L&G Clean Energy ETF USD Acc | 0.81% | 391K | $10.0M | −8,031 (−2.0%) | September 30, 2026 |
| 11 | Nuveen Quant Small Cap Equity R6 | 0.69% | 334K | $8.6M | — | August 31, 2026 |
| 12 | Emerald Growth A | 0.67% | 322K | $8.3M | — | August 31, 2026 |
| 13 | Vanguard Explorer Inv | 0.64% | 312K | $8.0M | −112,220 (−26.4%) | June 30, 2026 |
| 14 | Vanguard Russell 2000 ETF | 0.58% | 279K | $7.2M | +7,905 (+2.9%) | September 30, 2026 |
| 15 | GS Glb Sm Cp CORE Eq Base Inc USD Snap | 0.53% | 257K | $6.6M | +52,631 (+25.7%) | July 31, 2026 |
| 16 | Schwab US Small-Cap ETF™ | 0.53% | 256K | $6.6M | +171 (+0.1%) | September 30, 2026 |
| 17 | Baillie Gifford Global Discovery A Acc | 0.49% | 239K | $6.1M | +9,028 (+3.9%) | August 31, 2026 |
| 18 | Fidelity Extended Market Index | 0.49% | 235K | $6.0M | −1,700 (−0.7%) | August 31, 2026 |
| 19 | Principal SmallCap Growth I Instl | 0.43% | 211K | $5.4M | −260 (−0.1%) | September 30, 2026 |
| 20 | Royce Small-Cap Opportunity Invmt | 0.40% | 193K | $5.0M | +42,047 (+27.8%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
AMSC insider transactions
latest 7| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-02-24 | David R Oliver Jr | Sell | $34.10 | 200 | $6,820 |
| 2025-08-08 | Arthur H House | Sell | $50.92 | 9,703 | $494,077 |
| 2025-08-04 | Daniel P Mcgahn | Sell | $54.49 | 100,848 | $5.5M |
| 2025-06-06 | Daniel P Mcgahn | Sell | $31.82 | 7,689 | $244,664 |
| 2025-06-06 | John W Kosiba Jr | Sell | $31.83 | 4,744 | $151,002 |
| 2025-05-27 | Daniel P Mcgahn | Sell | $26.39 | 122,655 | $3.2M |
| 2025-05-27 | John W Kosiba Jr | Sell | $26.40 | 50,000 | $1.3M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
AMSC shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns AMSC
Institutional investors own 75.0% of American Superconductor's shares and insiders 3.45%. The largest holder is BlackRock Inc with 8.45% of the shares (4.1M), as of June 30, 2026. Among the top 20 institutions, 14 added shares and 5 reduced their stake in the latest filings. Short interest is 8.34% of the float, or 5.54 days of average trading volume. The share count rose 412.7% since 2014.
Related: AMSC analyst forecast, AMSC key metrics. See the AMSC stock overview for the latest quote and news.
AMSC ownership FAQ
Who owns the most American Superconductor stock?
The largest shareholders of American Superconductor are BlackRock Inc (8.45%), Vanguard Capital Management, LLC (4.20%), Barrow Hanley Mewhinney & Strauss LLC (3.52%), UBS Group AG (2.95%), Vanguard Portfolio Management, LLC (2.93%).
What percentage of American Superconductor is owned by institutions?
Institutions hold 75.0% of American Superconductor's shares outstanding; insiders hold 3.45%.
Which funds own American Superconductor?
The largest fund holders of American Superconductor are Vanguard MStar Total Stk Mkt Idx Invest (2.98%), iShares Russell 2000 ETF (2.54%), Oberweis Micro-Cap (1.91%), First Trust NASDAQ® Cln Edge®StGidIfsETF (1.37%), Fidelity Small Cap Index (1.07%).
What is American Superconductor's short interest?
3.9M shares of American Superconductor were sold short, 8.34% of the float; at the average daily volume it would take 5.54 days to cover.
Are insiders buying or selling American Superconductor?
Of the latest 7 reported insider transactions in American Superconductor (since May 27, 2025), 0 were purchases and 7 were sales.
How many shares of American Superconductor are outstanding?
American Superconductor has 48.4M shares outstanding, of which 46.8M are in the public float.