IBB vs VWO: Correlation & Overlap
How closely do iShares Biotechnology ETF (IBB) and Vanguard FTSE Emerging Markets ETF (VWO) trade together? Their weekly returns over three years give a correlation of 0.51, which is moderate. By holdings, the two funds overlap 0.0% by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and VWO?
Over the past 3 years, IBB and VWO moved with a correlation of 0.51, which is moderate. The link has loosened recently: the 1-year correlation (0.37) runs below the 3-year figure (0.51). Over 5 years the correlation is 0.48, and the annualized covariance of weekly returns is 159.5 %².
Within IBB's tracked universe of 168 assets, VWO comes in at #90 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IBB outperformed by 33.8 percentage points (+55.4% for IBB against +21.6% for VWO). The rolling one-year correlation moved between 0.35 and 0.69 over the past three years, a moderate range.
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 VWO: side by side
| IBB (iShares Biotechnology ETF) | VWO (Vanguard FTSE Emerging Markets ETF) | |
|---|---|---|
| 1-year return | +55.4% | +21.6% |
| 5-year return | +26.6% | +38.2% |
| Volatility (ann.) | 20.7% | 15.2% |
| Beta vs S&P 500 | 0.81 | 0.75 |
| Max drawdown (3Y) | -24.9% | -17.4% |
| Dividend yield | 0.22% | 2.36% |
| Expense ratio | 0.44% | 0.06% |
| Assets under management | $9.2B | $162.0B |
| Sector / category | ETF · Thematic | ETF · International |
On the fund side, IBB sits in the Health category at iShares, with $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. On the fund side, VWO sits in the Diversified Emerging Mkts category at Vanguard, with $162.0B under management, 4113 holdings, a 0.06% expense ratio, a 2.36% trailing dividend yield.
Portfolio overlap between IBB and VWO
The two portfolios are largely distinct. Weighing the shared positions, 0.0% of the two funds is identical, spread across 1 common holdings. That shared book is a large part of why the returns line up.
| Common holding | Weight in IBB | Weight in VWO |
|---|---|---|
| ALVO | 0.05% | 0.00% |
Largest positions held only by IBB: AMGN (8.43%), VRTX (7.89%), GILD (7.10%), REGN (5.68%), MRNA (3.76%). Only by VWO: 2330 (18.65%), 700 (3.97%), 9988 (2.90%), 2454 (1.62%), 939 (1.07%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26. Top 1 common positions shown.
Year-by-year returns
| Year | IBB | VWO |
|---|---|---|
| 2022 | -13.7% | -18.0% |
| 2023 | +3.8% | +9.3% |
| 2024 | -2.4% | +10.6% |
| 2025 | +28.0% | +25.6% |
| 2026 | +27.4% | +13.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and VWO good diversifiers for each other?
To a limited degree. At 0.51 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 VWO?
The IBB/VWO correlation stands at 0.51 on a 3-year window (1 year: 0.37, 5 years: 0.48), computed from weekly returns as of 2026-08-27.
Is VWO a good diversifier for IBB?
To a limited degree. At 0.51 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
How much do IBB and VWO overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 0.0% by weight over 1 common positions.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-vwo.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-vwo/)
Free with attribution; caching and terms are described in the API documentation.
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Hubs: IBB correlations · VWO correlations
