ASPN vs FSLR: Correlation
Aspen Aerogels, Inc. (ASPN) and First Solar (FSLR) show a moderate relationship: their 3-year correlation of weekly returns is 0.42.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ASPN and FSLR?
Across a 3-year window, the weekly returns of ASPN and FSLR correlate at 0.42, moderate. Recent behaviour matches the longer record: 0.40 over 1 year against 0.42 over 3. Stretching to 5 years gives 0.40, with an annualized covariance of 2072.6 %².
Among the 14 assets we track against ASPN, FSLR ranks #6 by 3-year correlation. Correlation aside, the last 12 months split them widely, with FSLR ahead by 35.4 points (-25.5% versus +9.9%). Note the risk asymmetry: ASPN runs 1.6 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
ASPN vs FSLR: side by side
| ASPN (Aspen Aerogels, Inc.) | FSLR (First Solar) | |
|---|---|---|
| 1-year return | -25.5% | +9.9% |
| 5-year return | -88.1% | +119.6% |
| Volatility (ann.) | 88.3% | 56.2% |
| Beta vs S&P 500 | 2.05 | 1.14 |
| Max drawdown (3Y) | -91.9% | -60.0% |
| Market cap | $0.4B | $22.6B |
| P/E (trailing) | – | 12.7 |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | Information Technology |
Year-by-year returns
| Year | ASPN | FSLR |
|---|---|---|
| 2022 | -76.3% | +71.9% |
| 2023 | +33.8% | +15.0% |
| 2024 | -24.7% | +2.3% |
| 2025 | -76.2% | +48.2% |
| 2026 | +84.8% | -19.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ASPN and FSLR good diversifiers for each other?
Reasonably. At 0.42, ASPN and FSLR keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between ASPN and FSLR?
As of 2026-08-27, the correlation of weekly returns between ASPN and FSLR is 0.42 over 3 years, 0.40 over 1 year and 0.40 over 5 years.
Is FSLR a good diversifier for ASPN?
Reasonably. At 0.42, ASPN and FSLR keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.42 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/aspn-vs-fslr.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/aspn-vs-fslr/)
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Related comparisons
Hubs: ASPN correlations · FSLR correlations
