ALEC vs IBB: Correlation
How closely do Alector, Inc. (ALEC) and iShares Biotechnology ETF (IBB) trade together? Their weekly returns over three years give a correlation of 0.54, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ALEC and IBB?
On 3 years of weekly data the ALEC/IBB correlation comes out at 0.54, moderate. Little has changed lately, as the 1-year reading of 0.47 lands near the 3-year figure. The 5-year figure is 0.50, and annualized covariance runs at 1010.9 %².
In ALEC's tracked universe of 11 assets, IBB sits right near the top at #2. Correlation aside, the last 12 months split them widely, with IBB ahead by 55.8 points (-0.4% versus +55.4%). Risk is not evenly split, since ALEC carries 4.4 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.
ALEC vs IBB: side by side
| ALEC (Alector, Inc.) | IBB (iShares Biotechnology ETF) | |
|---|---|---|
| 1-year return | -0.4% | +55.4% |
| 5-year return | -90.9% | +26.6% |
| Volatility (ann.) | 90.5% | 20.7% |
| Beta vs S&P 500 | 2.06 | 0.81 |
| Max drawdown (3Y) | -89.2% | -24.9% |
| Market cap | $0.3B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.22% |
| Expense ratio | – | 0.44% |
| Assets under management | – | $9.2B |
| Sector / category | US Listed | ETF · Thematic |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | ALEC | IBB |
|---|---|---|
| 2022 | -55.3% | -13.7% |
| 2023 | -13.5% | +3.8% |
| 2024 | -76.3% | -2.4% |
| 2025 | -17.5% | +28.0% |
| 2026 | +53.2% | +27.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ALEC and IBB good diversifiers for each other?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between ALEC and IBB?
Using weekly returns as of 2026-08-27: 0.54 over 3 years, with 0.47 over the last year and 0.50 over 5 years.
Is IBB a good diversifier for ALEC?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.54 mean?
On the −1 to +1 scale, 0.54 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/alec-vs-ibb.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/alec-vs-ibb/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ALEC correlations · IBB correlations
