BLFS vs IWM: Correlation
How closely do BioLife Solutions, Inc. (BLFS) and iShares Russell 2000 ETF (IWM) trade together? Their weekly returns over three years give a correlation of 0.60, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BLFS and IWM?
On 3 years of weekly data the BLFS/IWM correlation comes out at 0.60, strong. Lately the two have drifted apart, with the 1-year correlation at 0.46 versus 0.60 over 3 years. The 5-year figure is 0.59, and annualized covariance runs at 598.1 %².
Few assets follow BLFS as closely as IWM, which ranks #3 of 15 tracked partners. Correlation aside, the last 12 months split them widely, with BLFS ahead by 17.9 points (+46.3% versus +28.4%). One caveat on sizing: BLFS is 2.5 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.
BLFS vs IWM: side by side
| BLFS (BioLife Solutions, Inc.) | IWM (iShares Russell 2000 ETF) | |
|---|---|---|
| 1-year return | +46.3% | +28.4% |
| 5-year return | -36.2% | +41.5% |
| Volatility (ann.) | 50.1% | 19.8% |
| Beta vs S&P 500 | 1.66 | 1.06 |
| Max drawdown (3Y) | -37.0% | -27.5% |
| Market cap | $1.8B | – |
| P/E (trailing) | 37.2 | – |
| Dividend yield | 0.00% | 0.91% |
| Expense ratio | – | 0.19% |
| Assets under management | – | $80.1B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
IWM, iShares's Small Blend fund, carries $80.1B under management, 1757 holdings, a 0.19% expense ratio, a 0.91% trailing dividend yield.
Year-by-year returns
| Year | BLFS | IWM |
|---|---|---|
| 2022 | -51.2% | -20.5% |
| 2023 | -10.7% | +16.8% |
| 2024 | +59.8% | +11.4% |
| 2025 | -6.9% | +12.7% |
| 2026 | +53.8% | +22.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that IWM holds BLFS at a 0.05% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are BLFS and IWM good diversifiers for each other?
Only partially. A correlation of 0.60 means BLFS and IWM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between BLFS and IWM?
Using weekly returns as of 2026-08-27: 0.60 over 3 years, with 0.46 over the last year and 0.59 over 5 years.
Is IWM a good diversifier for BLFS?
Only partially. A correlation of 0.60 means BLFS and IWM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.60 mean?
A reading of 0.60 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/blfs-vs-iwm.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/blfs-vs-iwm/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: BLFS correlations · IWM correlations
