IBB vs IEMG: Correlation & Overlap
Measured on weekly returns over the past three years, iShares Biotechnology ETF (IBB) and iShares Core MSCI Emerging Markets ETF (IEMG) carry a correlation of 0.48, a moderate link. The two funds also share 0.0% of their portfolios by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IBB and IEMG?
Across a 3-year window, the weekly returns of IBB and IEMG correlate at 0.48, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.30 versus 0.48 over 3 years. Stretching to 5 years gives 0.48, with an annualized covariance of 172.8 %².
Among the 168 assets we track against IBB, IEMG ranks #105 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IBB outperformed by 19.4 percentage points (+55.4% for IBB against +36.0% for IEMG). Across three years, the rolling one-year figure varied moderately, from 0.29 to 0.72.
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 IEMG: side by side
| IBB (iShares Biotechnology ETF) | IEMG (iShares Core MSCI Emerging Markets ETF) | |
|---|---|---|
| 1-year return | +55.4% | +36.0% |
| 5-year return | +26.6% | +50.7% |
| Volatility (ann.) | 20.7% | 17.4% |
| Beta vs S&P 500 | 0.81 | 0.84 |
| Max drawdown (3Y) | -24.9% | -17.2% |
| Dividend yield | 0.22% | 2.31% |
| Expense ratio | 0.44% | 0.09% |
| Assets under management | $9.2B | $152.2B |
| Sector / category | ETF · Thematic | ETF · International |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield. IEMG, iShares's Diversified Emerging Mkts fund, carries $152.2B under management, 1824 holdings, a 0.09% expense ratio, a 2.31% trailing dividend yield.
Portfolio overlap between IBB and IEMG
The two portfolios are largely distinct: 0.0% of the funds' weight sits in the same underlying holdings (1 common positions). Correlation tells you they move together; overlap tells you why.
| Common holding | Weight in IBB | Weight in IEMG |
|---|---|---|
| LEGN | 0.21% | 0.01% |
Largest positions held only by IBB: AMGN (8.43%), VRTX (7.89%), GILD (7.10%), REGN (5.68%), MRNA (3.76%). Only by IEMG: 2330 (13.28%), 005930 (6.27%), 000660 (4.78%), 700 (2.49%), 9988 (1.77%).
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 | IEMG |
|---|---|---|
| 2022 | -13.7% | -20.0% |
| 2023 | +3.8% | +11.5% |
| 2024 | -2.4% | +6.5% |
| 2025 | +28.0% | +32.6% |
| 2026 | +27.4% | +23.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IBB and IEMG good diversifiers for each other?
Reasonably. At 0.48, IBB and IEMG keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between IBB and IEMG?
The IBB/IEMG correlation stands at 0.48 on a 3-year window (1 year: 0.30, 5 years: 0.48), computed from weekly returns as of 2026-08-27.
Is IEMG a good diversifier for IBB?
Reasonably. At 0.48, IBB and IEMG keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
How much do IBB and IEMG 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-iemg.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/ibb-vs-iemg/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IBB correlations · IEMG correlations
