Nasdaq · CIK 0000880807
AMSC AMERICAN SUPERCONDUCTOR CORP /DE/
Insider trading from SEC Form 4. Last filing 22 d ago. Close $30.52 on Oct 9, 2026, +18% from the 52-week low and -54% from the high.
In brief
AMERICAN SUPERCONDUCTOR CORP /DE/ (AMSC) has 37 SEC Form 4 filings on file from 8 insiders, the latest filed on Sep 21, 2026. No insider bought or sold on the open market in the last 90 days; rows filed in that time are grants, exercises, tax withholding and other transactions that carry no view on the price.
22 open-market trades have been scored at AMSC. The newest: Laura A. Dambier (director) sold $151k of stock on Jun 11, 2026, filed Jun 12, 2026, scored 46 (moderate). The largest of the 22 shown: Daniel P McGahn (Chairman, President and CEO) sold $5.5M on Aug 4, 2025, scored 65 (notable). 3 insiders sold within 14 days of each other around Jun 11, 2026.
21 Form 144 notices of planned sales are on file, the latest filed Jun 11, 2026.
Last 90 days
Net insider value
$0
no open-market trades
Buys
0
$0 by 0 insiders
Sells
0
$0 by 0 insiders
Insiders on file
8
with a Form 4 at this company
Price and insider trades, last year
AMSCOct 9, 2026 · close 30.52
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value. Click a marked bar to open the signal.Charts by TradingView Lightweight Charts™
Signals
Open-market buys and sells at AMERICAN SUPERCONDUCTOR CORP /DE/, scored.
| Score | Insider | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 46Moderate | Laura A. Dambier director sell | $151k 4,000 shares | -21% | +52% from low-41% from high | |
| 39Weak | Daniel P McGahn Chairman, President and CEO sell | $604k 16,117 shares | -1% | +52% from low-41% from high | |
| 30Weak | John W Kosiba JR SVP, CFO & Treasurer sell | $254k 6,769 shares | -2% | +52% from low-41% from high | |
| 36Weak | Daniel P McGahn Chairman, President and CEO sell | $404k 9,670 shares | -1% | +67% from low-35% from high | |
| 29Weak | John W Kosiba JR SVP, CFO & Treasurer sell | $202k 4,835 shares | -1% | +67% from low-35% from high | |
| 45Moderate | Daniel P McGahn Chairman, President and CEO sell | $4.3M 85,418 shares | -7% | +97% from low-23% from high | |
| 42Moderate | John W Kosiba JR SVP, CFO & Treasurer sell | $1.9M 36,909 shares | -10% | +97% from low-23% from high | |
| 15Weak | David R Oliver Jr director sell | $6,820 200 shares | -0% | +113% from low-49% from high | |
| 10Weak | David R Oliver Jr director buy | $1,666 200 shares | +0% | - | |
| 38Weak | Arthur H House director sell | $494k 9,703 shares | -17% | +223% from low-10% from high | |
| 67Notable | John W Kosiba JR SVP, CFO & Treasurer sell | $3.3M 59,843 shares | -15% | +251% from low-2% from high | |
| 65Notable | Daniel P McGahn Chairman, President and CEO sell | $5.5M 100,848 shares | -8% | +251% from low-2% from high | |
| 15Weak | Margaret D. Klein director buy | $2,783 500 shares | +3% | - | |
| 22Weak | John W Kosiba JR SVP, CFO & Treasurer sell | $190k 6,642 shares | -2% | +88% from low-19% from high | |
| 28Weak | Daniel P McGahn Chairman, President and CEO sell | $366k 12,815 shares | -1% | +88% from low-19% from high | |
| 26Weak | Daniel P McGahn Chairman, President and CEO sell | $245k 7,689 shares | -1% | +99% from low-14% from high | |
| 21Weak | John W Kosiba JR SVP, CFO & Treasurer sell | $151k 4,744 shares | -1% | +99% from low-14% from high | |
| 40Moderate | John W Kosiba JR SVP, CFO & Treasurer sell | $1.3M 50,000 shares | -11% | +73% from low-26% from high | |
| 38Weak | Daniel P McGahn Chairman, President and CEO sell | $3.2M 122,655 shares | -9% | +73% from low-26% from high | |
| 27Weak | Daniel P McGahn Chairman, President and CEO sell | $314k 12,815 shares | -1% | +56% from low-33% from high | |
| 24Weak | John W Kosiba JR SVP, CFO & Treasurer sell | $291k 11,860 shares | -2% | +56% from low-33% from high | |
| 52Moderate | John W Kosiba JR SVP, CFO & Treasurer sell | $1.4M 50,000 shares | -12% | - |
Planned sales
Form 144 notices filed before a sale of restricted or control stock, newest first. The sale itself usually reaches a Form 4 within days. All planned sales
| Filed | Seller | Shares | Value | Sale date | Past 3 months |
|---|---|---|---|---|---|
| Jun 11, 2026 | DANIEL MCGAHN Officer, Director | 16,117 0.03% of outstanding | $604k | Jun 11, 2026 | $4.7M |
| Jun 11, 2026 | JOHN KOSIBA Officer | 6,769 0.01% of outstanding | $254k | Jun 11, 2026 | $2.1M |
| Jun 10, 2026 | Dambier Laura A. Director | 4,000 0.01% of outstanding | $161k | Jun 10, 2026 | none |
| Jun 8, 2026 | DANIEL MCGAHN Officer, Director | 9,670 0.02% of outstanding | $404k | Jun 8, 2026 | $4.3M |
| Jun 8, 2026 | JOHN KOSIBA Officer | 4,835 0.01% of outstanding | $202k | Jun 8, 2026 | $1.9M |
| Jun 3, 2026 | JOHN KOSIBA Officer | 6,447 0.01% of outstanding | $316k | Jun 3, 2026 | $1.5M |
| Jun 3, 2026 | DANIEL MCGAHN Officer, Director | 12,893 0.03% of outstanding | $630k | Jun 3, 2026 | $3.7M |
| Jun 2, 2026 | DANIEL MCGAHN Officer, Director | 72,525 0.15% of outstanding | $3.7M | Jun 2, 2026 | none |
| Jun 2, 2026 | JOHN KOSIBA Officer | 30,462 0.06% of outstanding | $1.5M | Jun 2, 2026 | none |
| Aug 8, 2025 | Arthur H House Director | 9,703 0.02% of outstanding | $493k | Aug 8, 2025 | none |
| Aug 4, 2025 | JOHN KOSIBA Officer | 50,000 0.11% of outstanding | $2.7M | Aug 4, 2025 | $2.0M |
| Aug 4, 2025 | DANIEL MCGAHN Officer, Director | 100,849 0.22% of outstanding | $5.5M | Aug 4, 2025 | $4.2M |
| Jun 11, 2025 | DANIEL MCGAHN Officer, Director | 12,815 0.03% of outstanding | $366k | Jun 11, 2025 | $3.8M |
| Jun 11, 2025 | JOHN KOSIBA JR. Officer | 6,642 0.02% of outstanding | $190k | Jun 11, 2025 | $1.8M |
| Jun 6, 2025 | JOHN KOSIBA JR. Officer | 4,744 0.01% of outstanding | $151k | Jun 6, 2025 | $1.6M |
| Jun 6, 2025 | DANIEL MCGAHN Officer, Director | 7,689 0.02% of outstanding | $245k | Jun 6, 2025 | $3.6M |
| May 27, 2025 | JOHN KOSIBA JR. Officer | 50,000 0.13% of outstanding | $1.3M | May 27, 2025 | $291k |
| May 27, 2025 | DANIEL MCGAHN Officer, Director | 122,655 0.31% of outstanding | $3.2M | May 27, 2025 | $314k |
| May 20, 2025 | DANIEL MCGAHN Officer, Director | 12,815 0.03% of outstanding | $314k | May 20, 2025 | none |
| May 20, 2025 | JOHN KOSIBA JR. Officer | 11,860 0.03% of outstanding | $291k | May 20, 2025 | none |
| Nov 5, 2024 | Kosiba John W JR Officer | 50,000 0.13% of outstanding | $1.4M | Nov 4, 2024 | none |
Transactions
The newest 50 of 65 rows filed, every code.
| Date | Insider | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Sep 18, 2026 | Barbara G. Littlefield director | AGrant or award Common Stock | +1,607 | $0.00 | $0 | 37,034 | 22 d ago |
| Jun 11, 2026 | Laura A. Dambier director | SOpen-market sale Common Stock | -4,000 | $37.63 | $151k | 14,992 | Jun 12, 2026 |
| Jun 11, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -11,508 | $37.28 | $429k | 1,136,538 | Jun 11, 2026 |
| Jun 11, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -5,026 | $37.33 | $188k | 336,120 | Jun 11, 2026 |
| Jun 11, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -1,743 | $37.85 | $66k | 334,377 | Jun 11, 2026 |
| Jun 11, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -4,609 | $37.85 | $174k | 1,131,929 | Jun 11, 2026 |
| Jun 8, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -4,992 | $41.39 | $207k | 1,152,724 | Jun 10, 2026 |
| Jun 8, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -3,286 | $41.50 | $136k | 342,695 | Jun 10, 2026 |
| Jun 8, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -4,678 | $42.19 | $197k | 1,148,046 | Jun 10, 2026 |
| Jun 8, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -1,549 | $42.35 | $66k | 341,146 | Jun 10, 2026 |
| Jun 1, 2026 | Daniel P McGahn Chairman, President and CEO | AGrant or award Common Stock10b5-1 | +60,000 | $0.00 | $0 | 1,243,134 | Jun 3, 2026 |
| Jun 1, 2026 | John W Kosiba JR SVP, CFO & Treasurer | AGrant or award Common Stock10b5-1 | +30,000 | $0.00 | $0 | 382,890 | Jun 3, 2026 |
| Jun 2, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -13,762 | $49.45 | $681k | 1,229,372 | Jun 3, 2026 |
| Jun 2, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -5,704 | $49.46 | $282k | 377,186 | Jun 3, 2026 |
| Jun 2, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -27,900 | $50.63 | $1.4M | 1,201,472 | Jun 3, 2026 |
| Jun 2, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -12,122 | $50.62 | $614k | 365,064 | Jun 3, 2026 |
| Jun 2, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -28,558 | $51.46 | $1.5M | 1,172,914 | Jun 3, 2026 |
| Jun 2, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -12,036 | $51.47 | $619k | 353,028 | Jun 3, 2026 |
| Jun 2, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -2,305 | $52.14 | $120k | 1,170,609 | Jun 3, 2026 |
| Jun 2, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -600 | $52.19 | $31k | 352,428 | Jun 3, 2026 |
| Jun 3, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -7,075 | $48.31 | $342k | 1,163,534 | Jun 3, 2026 |
| Jun 3, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -3,200 | $48.31 | $155k | 349,228 | Jun 3, 2026 |
| Jun 3, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -2,638 | $49.28 | $130k | 346,590 | Jun 3, 2026 |
| Jun 3, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -4,501 | $49.25 | $222k | 1,159,033 | Jun 3, 2026 |
| Jun 3, 2026 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -609 | $50.83 | $31k | 345,981 | Jun 3, 2026 |
| Jun 3, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -500 | $50.29 | $25k | 1,158,533 | Jun 3, 2026 |
| Jun 3, 2026 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -817 | $50.99 | $42k | 1,157,716 | Jun 3, 2026 |
| Apr 3, 2026 | David R Oliver Jr director | AGrant or award Common Stock | +3,116 | $0.00 | $0 | 63,823 | Apr 7, 2026 |
| Apr 3, 2026 | Terence Robert Donnelly director | AGrant or award Common Stock | +2,665 | $0.00 | $0 | 2,665 | Apr 7, 2026 |
| Apr 3, 2026 | Laura A. Dambier director | AGrant or award Common Stock | +3,116 | $0.00 | $0 | 18,992 | Apr 7, 2026 |
| Apr 3, 2026 | Arthur H House director | AGrant or award Common Stock | +3,116 | $0.00 | $0 | 51,779 | Apr 7, 2026 |
| Apr 3, 2026 | Margaret D. Klein director | AGrant or award Common Stock | +3,116 | $0.00 | $0 | 19,492 | Apr 7, 2026 |
| Apr 3, 2026 | Barbara G. Littlefield director | AGrant or award Common Stock | +3,116 | $0.00 | $0 | 35,427 | Apr 7, 2026 |
| Feb 24, 2026 | David R Oliver Jr director | SOpen-market sale Common Stock | -200 | $34.10 | $6,820 | 60,707 | Feb 26, 2026 |
| Jun 18, 2019 | David R Oliver Jr director | POpen-market purchase Common Stock | +200 | $8.33 | $1,666 | 60,907 | Nov 13, 2025 |
| Aug 6, 2025 | Arthur H House director | MOption exercise Common Stock | +9,703 | $6.80 | $66k | 58,366 | Aug 8, 2025 |
| Aug 8, 2025 | Arthur H House director | SOpen-market sale Common Stock | -9,703 | $50.92 | $494k | 48,663 | Aug 8, 2025 |
| Aug 6, 2025 | Arthur H House director | MOption exercise Stock Options (Right to Buy)derivative | -9,703 | $0.00 | $0 | 0 | Aug 8, 2025 |
| Aug 4, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock | -34,260 | $54.34 | $1.9M | 368,630 | Aug 6, 2025 |
| Aug 4, 2025 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock | -73,105 | $54.26 | $4.0M | 1,210,877 | Aug 6, 2025 |
| Aug 4, 2022 | Margaret D. Klein director | POpen-market purchase Common Stock | +500 | $5.57 | $2,783 | 16,376 | Aug 6, 2025 |
| Aug 4, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock | -15,740 | $55.13 | $868k | 352,890 | Aug 6, 2025 |
| Aug 4, 2025 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock | -27,743 | $55.11 | $1.5M | 1,183,134 | Aug 6, 2025 |
| Aug 4, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stockindirect: By 401(k) plan | -9,843 | $55.26 | $544k | 0 | Aug 6, 2025 |
| Jun 11, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -6,342 | $28.55 | $181k | 403,190 | Jun 12, 2025 |
| Jun 11, 2025 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -12,315 | $28.56 | $352k | 1,284,482 | Jun 12, 2025 |
| Jun 11, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -300 | $29.08 | $8,725 | 402,890 | Jun 12, 2025 |
| Jun 11, 2025 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -500 | $29.09 | $15k | 1,283,982 | Jun 12, 2025 |
| Jun 6, 2025 | Daniel P McGahn Chairman, President and CEO | SOpen-market sale Common Stock10b5-1 | -7,689 | $31.82 | $245k | 1,296,797 | Jun 9, 2025 |
| Jun 6, 2025 | John W Kosiba JR SVP, CFO & Treasurer | SOpen-market sale Common Stock10b5-1 | -4,744 | $31.83 | $151k | 409,532 | Jun 9, 2025 |
50 of 65 rows shown.
Insiders
Everyone who has filed a Form 4 here.
- Laura A. Dambierdirector
- Terence Robert Donnellydirector
- Arthur H Housedirector
- Margaret D. Kleindirector
- John W Kosiba JRSVP, CFO & Treasurer
- Barbara G. Littlefielddirector
- Daniel P McGahnChairman, President and CEO
- David R Oliver Jrdirector
Questions about AMSC
Answered from the filings on this page, as of the latest one.
Are insiders buying AMSC?
No. In the last 90 days no insider at AMERICAN SUPERCONDUCTOR CORP /DE/ bought or sold shares on the open market according to SEC Form 4 filings. The rows on file from that period are grants, exercises, tax withholding or other transactions, which carry no view on the price.
Who was the last insider to trade AMSC on the open market?
Laura A. Dambier (director) sold $151k of AMSC on Jun 11, 2026 and filed the Form 4 on Jun 12, 2026. InsiderTell scored 46 (moderate), with 3 insiders on the same side within 14 days.
How many insiders file Form 4 at AMERICAN SUPERCONDUCTOR CORP /DE/?
8 people have filed a Form 4 at AMERICAN SUPERCONDUCTOR CORP /DE/, among them Laura A. Dambier (director), Terence Robert Donnelly (director), Arthur H House (director). Officers, directors and holders of more than 10% of a share class must report their trades within two business days.
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.