ASPN vs ICLN: Correlation
Aspen Aerogels, Inc. (ASPN) and iShares Global Clean Energy ETF (ICLN) show a moderate relationship: their 3-year correlation of weekly returns is 0.44.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ASPN and ICLN?
Over the past 3 years, ASPN and ICLN moved with a correlation of 0.44, which is moderate. Recent behaviour matches the longer record: 0.39 over 1 year against 0.44 over 3. Over 5 years the correlation is 0.50, and the annualized covariance of weekly returns is 926.5 %².
ICLN is one of the assets that tracks ASPN most closely: it ranks #2 out of the 14 assets we track against ASPN. Correlation aside, the last 12 months split them widely, with ICLN ahead by 51.1 points (-25.5% versus +25.6%). Risk is not evenly split, since ASPN carries 3.7 times the volatility of the other side.
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 ICLN: side by side
| ASPN (Aspen Aerogels, Inc.) | ICLN (iShares Global Clean Energy ETF) | |
|---|---|---|
| 1-year return | -25.5% | +25.6% |
| 5-year return | -88.1% | -18.4% |
| Volatility (ann.) | 88.3% | 24.0% |
| Beta vs S&P 500 | 2.05 | 0.78 |
| Max drawdown (3Y) | -91.9% | -34.6% |
| Market cap | $0.4B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 1.05% |
| Expense ratio | – | 0.39% |
| Assets under management | – | $2.3B |
| Sector / category | US Listed | ETF · Thematic |
ICLN, iShares's Miscellaneous Sector fund, carries $2.3B under management, 102 holdings, a 0.39% expense ratio, a 1.05% trailing dividend yield.
Year-by-year returns
| Year | ASPN | ICLN |
|---|---|---|
| 2022 | -76.3% | -5.4% |
| 2023 | +33.8% | -20.4% |
| 2024 | -24.7% | -25.7% |
| 2025 | -76.2% | +47.0% |
| 2026 | +84.8% | +8.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ASPN and ICLN good diversifiers for each other?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between ASPN and ICLN?
As of 2026-08-27, the correlation of weekly returns between ASPN and ICLN is 0.44 over 3 years, 0.39 over 1 year and 0.50 over 5 years.
Is ICLN a good diversifier for ASPN?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.44 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-icln.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/aspn-vs-icln/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ASPN correlations · ICLN correlations
