IBB vs TWST: Correlation
How closely do iShares Biotechnology ETF (IBB) and Twist Bioscience Corporation (TWST) trade together? Their weekly returns over three years give a correlation of 0.63, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and TWST?
Across a 3-year window, the weekly returns of IBB and TWST correlate at 0.63, strong. Lately the two have drifted apart, with the 1-year correlation at 0.50 versus 0.63 over 3 years. Stretching to 5 years gives 0.65, with an annualized covariance of 985.0 %².
By 3-year correlation, TWST places #18 of the 168 assets tracked against IBB. Their recent paths diverged sharply: over the last 12 months TWST outperformed by 407.7 percentage points (+55.4% for IBB against +463.1% for TWST). One caveat on sizing: TWST is 3.7 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.
IBB vs TWST: side by side
| IBB (iShares Biotechnology ETF) | TWST (Twist Bioscience Corporation) | |
|---|---|---|
| 1-year return | +55.4% | +463.1% |
| 5-year return | +26.6% | +39.8% |
| Volatility (ann.) | 20.7% | 76.1% |
| Beta vs S&P 500 | 0.81 | 2.21 |
| Max drawdown (3Y) | -24.9% | -59.0% |
| Market cap | – | $9.6B |
| P/E (trailing) | – | – |
| Dividend yield | 0.22% | 0.00% |
| Expense ratio | 0.44% | – |
| Assets under management | $9.2B | – |
| Sector / category | ETF · Thematic | US Listed |
IBB is a Health fund from iShares: $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | IBB | TWST |
|---|---|---|
| 2022 | -13.7% | -69.2% |
| 2023 | +3.8% | +54.8% |
| 2024 | -2.4% | +26.1% |
| 2025 | +28.0% | -31.7% |
| 2026 | +27.4% | +382.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that IBB holds TWST at a 0.62% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are IBB and TWST good diversifiers for each other?
To a limited degree. At 0.63 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 IBB and TWST?
As of 2026-08-27, the correlation of weekly returns between IBB and TWST is 0.63 over 3 years, 0.50 over 1 year and 0.65 over 5 years.
Is TWST a good diversifier for IBB?
To a limited degree. At 0.63 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 0.63 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/ibb-vs-twst.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/ibb-vs-twst/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: IBB correlations · TWST correlations
