American Superconductor Corporation
US ˙ NasdaqGS ˙ US0301112076

SecurityAMSC / American Superconductor Corporation
InstitutionState Street Corp
Latest Disclosed Ownership1,261,071 shares
Latest Disclosed Value $ 42,687,253
State Street Corp reports 5.79% increase in ownership of AMSC / American Superconductor Corporation

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 1,261,071 shares of American Superconductor Corporation (US:AMSC) valued at $42,687,253 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 1,192,093 shares of American Superconductor Corporation. This represents a change in shares of 5.79% during the quarter. The current value of the position is $58,854,184 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,261,071 68,978 5.79 42,687 24.42 0.0015
2026-02-13 2025-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,192,093 56,215 4.95 34,308 -49.14 0.0012
2025-11-14 2025-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,135,878 115,713 11.34 67,460 80.23 0.0023
2025-08-14 2025-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,020,165 130,118 14.62 37,430 131.83 0.0014
2025-05-15 2025-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 890,047 -19,248 -2.12 16,145 -27.91 0.0007
2025-02-14 2024-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 909,295 3,045 0.34 22,396 4.71 0.0009
2024-11-14 2024-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 906,250 140,106 18.29 21,388 19.35 0.0009
2024-08-14 2024-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 766,144 432,029 129.31 17,920 297.08 0.0008
2024-05-15 2024-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 334,115 -5,242 -1.54 4,514 19.39 0.0002
2024-02-14 2023-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 339,357 230,865 212.79 3,780 361.54 0.0002
2023-11-14 2023-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 108,492 0 0.00 819 20.62 0.0000
2023-08-14 2023-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 108,492 -304 -0.28 679 27.15 0.0000
2023-05-15 2023-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 108,796 16,100 17.37 534 56.60 0.0000
2023-05-15 2022-12-31 13F/A-99 AMERICAN SUPERCONDUCTOR SHS NEW 030111207 92,696 -543,894 -85.44 341 -87.77 0.0000
2023-05-15 2022-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 92,696 -543,894 341 0.0000
2022-11-15 2022-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 636,590 32,937 5.46 2,788 -10.84 0.0002
2022-08-15 2022-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 603,653 -446,659 -42.53 3,127 -60.88 0.0002
2022-05-16 2022-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,050,312 -44,167 -4.04 7,993 -32.88 0.0004
2022-02-14 2021-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,094,479 87,442 8.68 11,908 -18.90 0.0006
2021-11-15 2021-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 1,007,037 8,003 0.80 14,683 -15.48 0.0008
2021-08-16 2021-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 999,034 38,123 3.97 17,373 -4.64 0.0009
2021-07-09 2021-03-31 13F/A-1 AMERICAN SUPERCONDUCTOR SHS NEW 030111207 960,911 79,864 9.06 18,219 -11.70 0.0010
2021-05-17 2021-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 960,911 79,864 18,219 0.0010
2021-02-16 2020-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 881,047 350,813 66.16 20,634 168.74 0.0013
2020-11-10 2020-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 530,234 -2,989 -0.56 7,678 77.12 0.0005
2020-08-14 2020-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 533,223 130,955 32.55 4,335 96.69 0.0003
2020-06-19 2020-03-31 13F/A-1 AMERICAN SUPERCONDUCTOR SHS NEW 030111207 402,268 33,981 9.23 2,204 -23.76 0.0002
2020-05-11 2020-03-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 402,268 33,981 2,204 193.5556
2020-02-06 2019-12-31 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 368,287 -11,756 -3.09 2,891 -2.99 0.0002
2019-11-14 2019-09-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 380,043 81,442 27.27 2,980 7.54 0.0002
2019-08-14 2019-06-30 13F AMERICAN SUPERCONDUCTOR SHS NEW 030111207 298,601 298,601 2,771 0.0002
2017-08-14 2017-06-30 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 0 -153,953 -100.00 0 -100.00
2017-05-15 2017-03-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 153,953 988 0.65 1,057 -6.21 0.0001
2017-02-09 2016-12-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 152,965 2,373 1.58 1,127 6.82 0.0001
2017-01-13 2016-09-30 13F/A-1 AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 150,592 13,395 9.76 1,055 -8.97 0.0001
2016-11-14 2016-09-30 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 150,592 1,055
2016-08-12 2016-06-30 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111207 137,197 137,197 1,159 0.0001
2015-05-15 2015-03-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 0 -32,631 -100.00 0 -100.00
2015-02-11 2014-12-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 32,631 -2,400 -6.85 24 -52.94 0.0000
2014-11-12 2014-09-30 13F/A-1 AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 35,031 0 0.00 51 -12.07 0.0000
2014-11-10 2014-09-30 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 35,031 51
2014-08-12 2014-06-30 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 35,031 -760,633 -95.60 58 -95.48 0.0000
2014-05-15 2014-03-31 13F/A-1 AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 795,664 28,363 3.70 1,282 1.91 0.0001
2014-05-13 2014-03-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 795,764 1,282
2014-02-06 2013-12-31 13F/A-1 AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 767,301 11,090 1.47 1,258 -28.89 0.0001
2014-02-06 2013-12-31 13F AMERICAN SUPERCONDUCTOR CP Common equity shares 030111108 802,979 2,101
2013-11-12 2013-09-30 13F AMERICAN SUPERCONDUCTOR CP Common Stock 030111108 756,211 41,663 5.83 1,769 -6.40 0.0002
2013-08-08 2013-06-30 13F AMERICAN SUPERCONDUCTOR CP Common Stock 030111108 714,548 714,548 1,890 0.0002
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.