ASPN vs TAN: Correlation
How closely do Aspen Aerogels, Inc. (ASPN) and Invesco Solar ETF (TAN) trade together? Their weekly returns over three years give a correlation of 0.43, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ASPN and TAN?
Over the past 3 years, ASPN and TAN moved with a correlation of 0.43, which is moderate. The relationship has been stable: the 1-year correlation (0.36) sits close to the 3-year figure. Over 5 years the correlation is 0.49, and the annualized covariance of weekly returns is 1408.0 %².
By 3-year correlation, TAN places #4 of the 14 assets tracked against ASPN. Their recent paths diverged sharply: over the last 12 months TAN outperformed by 46.9 percentage points (-25.5% for ASPN against +21.4% for TAN). One caveat on sizing: ASPN is 2.4 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.
ASPN vs TAN: side by side
| ASPN (Aspen Aerogels, Inc.) | TAN (Invesco Solar ETF) | |
|---|---|---|
| 1-year return | -25.5% | +21.4% |
| 5-year return | -88.1% | -41.9% |
| Volatility (ann.) | 88.3% | 37.4% |
| Beta vs S&P 500 | 2.05 | 1.04 |
| Max drawdown (3Y) | -91.9% | -55.4% |
| Market cap | $0.4B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | ASPN | TAN |
|---|---|---|
| 2022 | -76.3% | -5.2% |
| 2023 | +33.8% | -26.8% |
| 2024 | -24.7% | -37.6% |
| 2025 | -76.2% | +48.3% |
| 2026 | +84.8% | +1.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ASPN and TAN good diversifiers for each other?
A fair diversifier. At 0.43, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between ASPN and TAN?
Using weekly returns as of 2026-08-27: 0.43 over 3 years, with 0.36 over the last year and 0.49 over 5 years.
Is TAN a good diversifier for ASPN?
A fair diversifier. At 0.43, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.43 mean?
On the −1 to +1 scale, 0.43 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/aspn-vs-tan.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/aspn-vs-tan/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ASPN correlations · TAN correlations
