ALEC vs XBI: Correlation
Measured on weekly returns over the past three years, Alector, Inc. (ALEC) and SPDR S&P Biotech ETF (XBI) carry a correlation of 0.55, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ALEC and XBI?
Over the past 3 years, ALEC and XBI moved with a correlation of 0.55, which is moderate. The relationship has been stable: the 1-year correlation (0.47) sits close to the 3-year figure. Over 5 years the correlation is 0.57, and the annualized covariance of weekly returns is 1380.4 %².
Few assets follow ALEC as closely as XBI, which ranks #1 of 11 tracked partners. Correlation aside, the last 12 months split them widely, with XBI ahead by 87.6 points (-0.4% versus +87.2%). Risk is not evenly split, since ALEC carries 3.3 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 XBI: side by side
| ALEC (Alector, Inc.) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | -0.4% | +87.2% |
| 5-year return | -90.9% | +28.6% |
| Volatility (ann.) | 90.5% | 27.7% |
| Beta vs S&P 500 | 2.06 | 1.09 |
| Max drawdown (3Y) | -89.2% | -33.0% |
| Market cap | $0.3B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | ALEC | XBI |
|---|---|---|
| 2022 | -55.3% | -25.9% |
| 2023 | -13.5% | +7.6% |
| 2024 | -76.3% | +1.0% |
| 2025 | -17.5% | +35.9% |
| 2026 | +53.2% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ALEC and XBI good diversifiers for each other?
Somewhat, no more. With 0.55 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between ALEC and XBI?
Using weekly returns as of 2026-08-27: 0.55 over 3 years, with 0.47 over the last year and 0.57 over 5 years.
Is XBI a good diversifier for ALEC?
Somewhat, no more. With 0.55 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.55 mean?
On the −1 to +1 scale, 0.55 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-xbi.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/alec-vs-xbi/)
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Related comparisons
Hubs: ALEC correlations · XBI correlations
