AMSC
Amercn Supercond (AMSC)
NASDAQ
$42.11-$3.22 (-7.10%)
Price as of Jun 23, 2026 5:57 PM EDT
  • $2.2B
    Market Cap
  • 39.81%
    1-Year Change
  • Specialty Industrial Machinery
    Industry

Top Holders

Institutional
Mutual Funds
Holder
Ownership %
Shares Held
Change (Shares, %)
Report Date
BLACKROCK, INC.
8.35%
4.0M
+232,247 (+5.83%)
Mar 31, 2026
VANGUARD GROUP INC
7.39%
3.5M
+576,831 (+16.36%)
Dec 31, 2025
BLACKROCK FUNDING, INC. /DE
7.19%
3.4M
+707,110 (+20.63%)
Dec 31, 2024
BLACKROCK INC.
5.33%
2.5M
+1.8M (+70.67%)
Jun 30, 2024
N/A
4.28%
2.0M
+2.0M (+100.00%)
Mar 31, 2026
BAILLIE GIFFORD & CO
3.03%
1.4M
-59,422 (-4.11%)
Mar 31, 2026
STATE STREET CORP
2.64%
1.3M
+68,978 (+5.47%)
Mar 31, 2026

Current Ownership Distribution

  • Institutions394.1M (77.14%)
  • Mutual Funds113.7M (22.26%)
  • Insiders3.1M (0.60%)
  • Other0 (0.00%)

Insider Transactions

  • 0.60% (3.1M)
    Current InsiderOwnership (%, shares)
  • 0
    Number of InsiderBuying (last 12 months)
  • $0.00
    Amount of InsiderBuying (last 12 months)
  • 5
    Number of InsiderSelling (last 12 months)
  • $262.9M
    Amount of InsiderSelling (last 12 months)
Insider Name & Title
Type
Date
Transaction Value
Shares
Share Price
Shares After Transactions
Dambier Laura A.
Sell
Jun 11, 2026
$150,520.00
4,000
$37.63
14,992
McGahn Daniel P
Chairman, President and CEO
Sell
Jun 08, 2026
$206,614.39
4,992
$41.39
1.2M
McGahn Daniel P
Chairman, President and CEO
Sell
Jun 08, 2026
$197,381.19
4,678
$42.19
1.1M
Littlefield Barbara G.
Award
Apr 03, 2026
$0.00
3,116
$0.00
35,427
Donnelly Terence Robert
Award
Apr 03, 2026
$0.00
2,665
$0.00
2,665
House Arthur H
Award
Apr 03, 2026
$0.00
3,116
$0.00
51,779
OLIVER DAVID R JR
Award
Apr 03, 2026
$0.00
3,116
$0.00
63,823
Dambier Laura A.
Award
Apr 03, 2026
$0.00
3,116
$0.00
18,992
OLIVER DAVID R JR
Sell
Feb 24, 2026
$6,820.00
200
$34.10
60,707
House Arthur H
Sell
Aug 08, 2025
$494,081.61
9,703
$50.92
48,663
House Arthur H
Exempt
Aug 06, 2025
$0.00
9,703
$0.00
0
House Arthur H
Exempt
Aug 06, 2025
$65,980.40
9,703
$6.80
58,366
McGahn Daniel P
Chairman, President and CEO
Sell
Aug 04, 2025
$4.0M
73,105
$54.26
1.2M
Kosiba John W JR
SVP, CFO & Treasurer
Sell
Aug 04, 2025
$1.9M
34,260
$54.34
368,630
McGahn Daniel P
Chairman, President and CEO
Sell
Aug 04, 2025
$1.5M
27,743
$55.11
1.2M
Kosiba John W JR
SVP, CFO & Treasurer
Sell
Aug 04, 2025
$867,733.61
15,740
$55.13
352,890
Kosiba John W JR
SVP, CFO & Treasurer
Sell
Aug 04, 2025
$543,924.18
9,843
$55.26
0
McGahn Daniel P
Chairman, President and CEO
Sell
Jun 11, 2025
$351,696.70
12,315
$28.56
1.3M
McGahn Daniel P
Chairman, President and CEO
Sell
Jun 11, 2025
$14,545.00
500
$29.09
1.3M
McGahn Daniel P
Chairman, President and CEO
Sell
Jun 06, 2025
$244,670.13
7,689
$31.82
1.3M
McGahn Daniel P
Chairman, President and CEO
Sell
May 27, 2025
$626,052.33
24,506
$25.55
1.4M
Kosiba John W JR
SVP, CFO & Treasurer
Sell
May 27, 2025
$258,021.77
10,097
$25.55
454,179
McGahn Daniel P
Chairman, President and CEO
Sell
May 27, 2025
$2.6M
98,149
$26.60
1.3M
Donnelly Terence Robert
Award
May 27, 2025
$0.00
2,112
$0.00
2,112
Kosiba John W JR
SVP, CFO & Treasurer
Sell
May 27, 2025
$1.1M
39,903
$26.61
414,276
Kosiba John W JR
SVP, CFO & Treasurer
Sell
May 20, 2025
$290,529.68
11,860
$24.50
464,276
McGahn Daniel P
Chairman, President and CEO
Sell
May 20, 2025
$313,877.79
12,815
$24.49
1.4M
House Arthur H
Award
Apr 03, 2025
$0.00
2,639
$0.00
48,663
Dambier Laura A.
Award
Apr 03, 2025
$0.00
2,639
$0.00
15,876
Littlefield Barbara G.
Award
Apr 03, 2025
$0.00
2,639
$0.00
32,311