AMSC vs ECF: Correlation
Measured on weekly returns over the past three years, American Superconductor Corporation (AMSC) and Ellsworth Growth and Income Fund Ltd. (ECF) carry a correlation of 0.49, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AMSC and ECF?
Across a 3-year window, the weekly returns of AMSC and ECF correlate at 0.49, moderate. Recent behaviour matches the longer record: 0.59 over 1 year against 0.49 over 3. Stretching to 5 years gives 0.48, with an annualized covariance of 634.2 %².
Within AMSC's tracked universe of 13 assets, ECF comes in at #5 by 3-year correlation. The last year tells two different stories: ECF led by 65.6 percentage points, -42.7% for AMSC against +22.9% for ECF. One caveat on sizing: AMSC is 4.8 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
AMSC vs ECF: side by side
| AMSC (American Superconductor Corporation) | ECF (Ellsworth Growth and Income Fund Ltd.) | |
|---|---|---|
| 1-year return | -42.7% | +22.9% |
| 5-year return | +141.8% | +25.8% |
| Volatility (ann.) | 78.4% | 16.5% |
| Beta vs S&P 500 | 2.16 | 0.71 |
| Max drawdown (3Y) | -61.1% | -16.8% |
| Market cap | $1.4B | $0.2B |
| P/E (trailing) | 9.6 | 3.9 |
| Dividend yield | 0.00% | 7.38% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | AMSC | ECF |
|---|---|---|
| 2022 | -66.2% | -31.6% |
| 2023 | +202.7% | +8.0% |
| 2024 | +121.1% | +27.5% |
| 2025 | +16.8% | +30.0% |
| 2026 | +3.7% | +10.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AMSC and ECF good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.49 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between AMSC and ECF?
As of 2026-08-27, the correlation of weekly returns between AMSC and ECF is 0.49 over 3 years, 0.59 over 1 year and 0.48 over 5 years.
Is ECF a good diversifier for AMSC?
Yes, to a useful degree: a correlation of 0.49 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.49 mean?
On the −1 to +1 scale, 0.49 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/amsc-vs-ecf.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/amsc-vs-ecf/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: AMSC correlations · ECF correlations
