ESSEX INVESTMENT MANAGEMENT CO LLC AMSC — AMERICAN SUPERCONDUCTOR COMMON

Ownership history in ESSEX INVESTMENT MANAGEMENT CO LLC  ·  32 quarters on record

AI Ownership Summary

ESSEX INVESTMENT MANAGEMENT CO LLC reported AMERICAN SUPERCONDUCTOR COMMON (AMSC) in 32 quarterly 13F filings from 2024 Q1 through 2026 Q2. Peak portfolio weight reached 2.53% in 2024 Q2. The latest visible filing shows AMSC at 1.21% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings. Older history is available after unlock; the visible window still shows the most recent pattern.

What this AMSC ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was ESSEX INVESTMENT MANAGEMENT CO LLC's position in AMERICAN SUPERCONDUCTOR COMMON, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2026 Q2

AMSC was reported at 1.21% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
2.53% in 2024 Q2

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2024 Q1 to 2026 Q2

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

AMSC stock page ESSEX INVESTMENT MANAGEMENT CO LLC fund profile ESSEX INVESTMENT MANAGEMENT CO LLC full holdings
How ESSEX INVESTMENT MANAGEMENT CO LLC held AMSC — position size vs. price
% of Fund (quarterly)    AMSC price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 10 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2026 Q2 REDUCED — — — 221,933 -5,625 -2.5% 1.21% $9.2M 2026-08-06 $32.90
2026 Q1 ADDED — — — 227,558 +12,404 +5.8% 1.22% $7.7M 2026-05-11 $58.72
2025 Q4 REDUCED 12.4% +17.6% ❌ 215,154 -30,427 -12.4% 0.94% $6.2M 2026-02-13 $34.26
2025 Q3 REDUCED 29.0% -50.8% ✅ 245,581 -100,461 -29.0% 2.23% $14.6M 2025-11-06 $36.55
2025 Q2 REDUCED 7.0% +65.8% ❌ 346,042 -26,179 -7.0% 2.31% $12.7M 2025-08-12 $55.89
2025 Q1 REDUCED 13.4% +102.3% ❌ 372,221 -57,655 -13.4% 1.41% $6.8M 2025-05-07 $20.72
2024 Q4 REDUCED 7.5% -26.4% ✅ 429,876 -34,630 -7.5% 1.90% $10.6M 2025-02-07 $32.85
2024 Q3 REDUCED 19.6% +6.8% ❌ 464,506 -113,120 -19.6% 1.91% $11.0M 2024-10-10 $22.17
2024 Q2 REDUCED — — — 577,626 -6,298 -1.1% 2.53% $13.5M 2024-08-12 $19.72
2024 Q1 REDUCED 6.4% +70.1% ❌ 583,924 -40,094 -6.4% 1.56% $7.9M 2024-05-03 $13.37
22 older quarters hidden  —  Sign in free or upgrade to Premium to see full history

🏢 Other funds also holding AMSC

As of 2026 Q2 — sorted by position size

AWM Investment Company, Inc. 3Y 7Y 3.43% Palisades Investment Partners, LLC 3Y 7Y 1.85% Telemark Asset Management, LLC 3Y 7Y 1.8% Ranger Investment Management, L.P. 3Y 7Y 1.06% Covestor Ltd 3Y 0.99% Lumbard & Kellner, LLC 3Y 7Y 0.93% OBERWEIS ASSET MANAGEMENT INC/ 3Y 7Y 0.85% EMERALD ADVISERS, LLC 3Y 7Y 0.82% EMERALD MUTUAL FUND ADVISERS TRUST 3Y 7Y 0.79% nVerses Capital, LLC 0.76%

FAQ About ESSEX INVESTMENT MANAGEMENT CO LLC and AMSC

These are the practical questions this page is built to answer before you even open the full history table.

How long has ESSEX INVESTMENT MANAGEMENT CO LLC reported owning AMSC?

ESSEX INVESTMENT MANAGEMENT CO LLC reported AMSC across 10 quarterly 13F filings, from 2024 Q1 through 2026 Q2.

What was the largest reported AMSC position in ESSEX INVESTMENT MANAGEMENT CO LLC's portfolio?

The largest reported portfolio weight for AMSC was 2.53% in 2024 Q2.

What is the latest reported AMSC position on this page?

The most recent filing on this page is 2026 Q2, when ESSEX INVESTMENT MANAGEMENT CO LLC reported 221,933 shares, equal to 1.21% of portfolio, with an estimated market value of $9.2M.

What does the chart on this AMSC ownership page compare?

The chart compares ESSEX INVESTMENT MANAGEMENT CO LLC's quarterly AMSC portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

How well did ESSEX INVESTMENT MANAGEMENT CO LLC time their AMSC position?

Based on 13F filing dates vs. subsequent AMSC price moves, ESSEX INVESTMENT MANAGEMENT CO LLC correctly timed 12 out of 31 reported position changes (39%). The annualised alpha on AMSC relative to SPY over the holding period was +35.1%.

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