IBB vs VT: Correlation & Overlap
How closely do iShares Biotechnology ETF (IBB) and Vanguard Total World Stock ETF (VT) trade together? Their weekly returns over three years give a correlation of 0.61, which is strong. The two funds also share 1.1% of their portfolios by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and VT?
Across a 3-year window, the weekly returns of IBB and VT correlate at 0.61, strong. The link has loosened recently: the 1-year correlation (0.42) runs below the 3-year figure (0.61). Stretching to 5 years gives 0.66, with an annualized covariance of 176.1 %².
Within IBB's tracked universe of 168 assets, VT comes in at #29 by 3-year correlation. The last year tells two different stories: IBB led by 32.7 percentage points, +55.4% for IBB against +22.7% for VT. The rolling one-year correlation moved between 0.45 and 0.85 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 VT: side by side
| IBB (iShares Biotechnology ETF) | VT (Vanguard Total World Stock ETF) | |
|---|---|---|
| 1-year return | +55.4% | +22.7% |
| 5-year return | +26.6% | +67.7% |
| Volatility (ann.) | 20.7% | 13.9% |
| Beta vs S&P 500 | 0.81 | 0.92 |
| Max drawdown (3Y) | -24.9% | -16.5% |
| Dividend yield | 0.22% | 1.59% |
| Expense ratio | 0.44% | 0.06% |
| Assets under management | $9.2B | $97.9B |
| Sector / category | ETF · Thematic | ETF · Global |
IBB is a Health fund from iShares: $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. VT is a Global Large-Stock Blend fund from Vanguard: $97.9B under management, 5308 holdings, a 0.06% expense ratio, a 1.59% trailing dividend yield.
Portfolio overlap between IBB and VT
The two portfolios are largely distinct: 1.1% of the funds' weight sits in the same underlying holdings (65 common positions). Correlation tells you they move together; overlap tells you why.
| Common holding | Weight in IBB | Weight in VT |
|---|---|---|
| AMGN | 8.43% | 0.19% |
| GILD | 7.10% | 0.15% |
| VRTX | 7.89% | 0.11% |
| REGN | 5.68% | 0.07% |
| ARGX | 3.76% | 0.05% |
| NTRA | 3.19% | 0.03% |
| RVMD | 2.83% | 0.03% |
| ILMN | 2.34% | 0.03% |
| BIIB | 2.23% | 0.03% |
| ALNY | 2.19% | 0.02% |
| EBS | 0.02% | 0.03% |
| UTHR | 1.46% | 0.02% |
| INSM | 1.84% | 0.02% |
| INCY | 1.75% | 0.02% |
| MRNA | 3.76% | 0.02% |
Largest positions held only by IBB: ONC (2.07%), ASND (1.07%), BNTX (0.71%), APGE (0.53%), SYRE (0.50%). Only by VT: NVDA (4.20%), AAPL (4.00%), MSFT (3.09%), AMZN (2.36%), GOOGL (1.89%).
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 | IBB | VT |
|---|---|---|
| 2022 | -13.7% | -18.0% |
| 2023 | +3.8% | +22.0% |
| 2024 | -2.4% | +16.5% |
| 2025 | +28.0% | +22.4% |
| 2026 | +27.4% | +15.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and VT 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 IBB and VT?
Using weekly returns as of 2026-08-27: 0.61 over 3 years, with 0.42 over the last year and 0.66 over 5 years.
Is VT a good diversifier for IBB?
Somewhat, no more. With 0.61 correlation, most large moves hit both names, and the diversification benefit stays modest.
How much do IBB and VT overlap?
The two funds share 65 holdings amounting to 1.1% of weight, per issuer portfolio files dated 2026-08-26.
Use this data
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Related comparisons
Hubs: IBB correlations · VT correlations
