IBB vs SPYG: Correlation & Overlap
How closely do iShares Biotechnology ETF (IBB) and SPDR Portfolio S&P 500 Growth ETF (SPYG) trade together? Their weekly returns over three years give a correlation of 0.46, which is moderate. Looking through to holdings, 0.8% of the two portfolios is the same by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and SPYG?
Over the past 3 years, IBB and SPYG moved with a correlation of 0.46, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.29 versus 0.46 over 3 years. Over 5 years the correlation is 0.57, and the annualized covariance of weekly returns is 180.2 %².
By 3-year correlation, SPYG places #122 of the 168 assets tracked against IBB. The last year tells two different stories: IBB led by 33.0 percentage points, +55.4% for IBB against +22.4% for SPYG. Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from 0.30 to 0.80.
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 SPYG: side by side
| IBB (iShares Biotechnology ETF) | SPYG (SPDR Portfolio S&P 500 Growth ETF) | |
|---|---|---|
| 1-year return | +55.4% | +22.4% |
| 5-year return | +26.6% | +85.9% |
| Volatility (ann.) | 20.7% | 18.9% |
| Beta vs S&P 500 | 0.81 | 1.25 |
| Max drawdown (3Y) | -24.9% | -22.1% |
| Dividend yield | 0.22% | 0.49% |
| Expense ratio | 0.44% | 0.04% |
| Assets under management | $9.2B | $52.2B |
| Sector / category | ETF · Thematic | ETF · US Style |
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. SPYG is a Large Growth fund from State Street Investment Management: $52.2B under management, 148 holdings, a 0.04% expense ratio, a 0.49% trailing dividend yield.
Portfolio overlap between IBB and SPYG
The two portfolios are largely distinct: 0.8% of the funds' weight sits in the same underlying holdings (3 common positions). Correlation tells you they move together; overlap tells you why.
Largest positions held only by IBB: VRTX (7.89%), REGN (5.68%), MRNA (3.76%), ARGX (3.76%), NTRA (3.19%). Only by SPYG: NVDA (14.21%), MSFT (10.32%), AAPL (6.44%), GOOGL (5.61%), AVGO (4.71%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26. Top 3 common positions shown.
Year-by-year returns
| Year | IBB | SPYG |
|---|---|---|
| 2022 | -13.7% | -29.4% |
| 2023 | +3.8% | +30.0% |
| 2024 | -2.4% | +36.0% |
| 2025 | +28.0% | +22.1% |
| 2026 | +27.4% | +14.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and SPYG good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.46 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between IBB and SPYG?
The IBB/SPYG correlation stands at 0.46 on a 3-year window (1 year: 0.29, 5 years: 0.57), computed from weekly returns as of 2026-08-27.
Is SPYG a good diversifier for IBB?
Yes, to a useful degree: a correlation of 0.46 leaves real independence between the two, which historically damped combined volatility.
How much do IBB and SPYG overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 0.8% by weight over 3 common positions.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ibb-vs-spyg.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/ibb-vs-spyg/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: IBB correlations · SPYG correlations
