ACWI vs IBB: Correlation & Overlap
iShares MSCI ACWI ETF (ACWI) and iShares Biotechnology ETF (IBB) show a strong relationship: their 3-year correlation of weekly returns is 0.61. The two funds also share 1.0% of their portfolios by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ACWI and IBB?
Over the past 3 years, ACWI and IBB moved with a correlation of 0.61, which is strong. Lately the two have drifted apart, with the 1-year correlation at 0.41 versus 0.61 over 3 years. Over 5 years the correlation is 0.65, and the annualized covariance of weekly returns is 172.6 %².
By 3-year correlation, IBB places #70 of the 119 assets tracked against ACWI. Their recent paths diverged sharply: over the last 12 months IBB outperformed by 32.7 percentage points (+22.7% for ACWI against +55.4% for IBB). Across three years, the rolling one-year figure varied moderately, from 0.45 to 0.85.
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.
ACWI vs IBB: side by side
| ACWI (iShares MSCI ACWI ETF) | IBB (iShares Biotechnology ETF) | |
|---|---|---|
| 1-year return | +22.7% | +55.4% |
| 5-year return | +69.0% | +26.6% |
| Volatility (ann.) | 13.8% | 20.7% |
| Beta vs S&P 500 | 0.92 | 0.81 |
| Max drawdown (3Y) | -16.5% | -24.9% |
| Dividend yield | 1.44% | 0.22% |
| Expense ratio | 0.32% | 0.44% |
| Assets under management | $32.5B | $9.2B |
| Sector / category | ETF · Global | ETF · Thematic |
On the fund side, ACWI sits in the Global Large-Stock Blend category at iShares, with $32.5B under management, 1590 holdings, a 0.32% expense ratio, a 1.44% trailing dividend yield. IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Portfolio overlap between ACWI and IBB
The two portfolios are largely distinct: 1.0% of the funds' weight sits in the same underlying holdings (17 common positions). Correlation tells you they move together; overlap tells you why.
| Common holding | Weight in ACWI | Weight in IBB |
|---|---|---|
| AMGN | 0.23% | 8.43% |
| GILD | 0.18% | 7.10% |
| VRTX | 0.13% | 7.89% |
| REGN | 0.08% | 5.68% |
| ARGX | 0.06% | 3.76% |
| NTRA | 0.04% | 3.19% |
| BIIB | 0.03% | 2.23% |
| ILMN | 0.03% | 2.34% |
| INSM | 0.03% | 1.84% |
| ALNY | 0.03% | 2.19% |
| RVMD | 0.03% | 2.83% |
| INCY | 0.02% | 1.75% |
| EBS | 0.04% | 0.02% |
| GMAB | 0.02% | 1.22% |
| UTHR | 0.02% | 1.46% |
Largest positions held only by ACWI: NVDA (4.64%), AAPL (4.41%), MSFT (3.35%), AMZN (2.41%), GOOGL (1.91%). Only by IBB: MRNA (3.76%), ONC (2.07%), ROIV (1.31%), ASND (1.07%), MEDP (0.98%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26. Top 15 common positions shown.
Year-by-year returns
| Year | ACWI | IBB |
|---|---|---|
| 2022 | -18.4% | -13.7% |
| 2023 | +22.3% | +3.8% |
| 2024 | +17.4% | -2.4% |
| 2025 | +22.4% | +28.0% |
| 2026 | +14.9% | +27.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ACWI and IBB good diversifiers for each other?
Somewhat, no more. With 0.61 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between ACWI and IBB?
The ACWI/IBB correlation stands at 0.61 on a 3-year window (1 year: 0.41, 5 years: 0.65), computed from weekly returns as of 2026-08-27.
Is IBB a good diversifier for ACWI?
Somewhat, no more. With 0.61 correlation, most large moves hit both names, and the diversification benefit stays modest.
How much do ACWI and IBB overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 1.0% by weight over 17 common positions.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/acwi-vs-ibb.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/acwi-vs-ibb/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ACWI correlations · IBB correlations
