IEF vs KOS: Correlation
How closely do iShares 7-10 Year Treasury Bond ETF (IEF) and Kosmos Energy Ltd. (KOS) trade together? Their weekly returns over three years give a correlation of -0.27, which is negative.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IEF and KOS?
Over the past 3 years, IEF and KOS moved with a correlation of -0.27, which is negative, meaning they tend to move in opposite directions. The link has loosened recently: the 1-year correlation (-0.38) runs below the 3-year figure (-0.27). Over 5 years the correlation is -0.19, and the annualized covariance of weekly returns is -117.9 %².
By 3-year correlation, KOS places #40 of the 48 assets tracked against IEF. Correlation aside, the last 12 months split them widely, with KOS ahead by 55.9 points (+0.9% versus +56.8%). One caveat on sizing: KOS is 10.4 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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.
IEF vs KOS: side by side
| IEF (iShares 7-10 Year Treasury Bond ETF) | KOS (Kosmos Energy Ltd.) | |
|---|---|---|
| 1-year return | +0.9% | +56.8% |
| 5-year return | -7.9% | +24.8% |
| Volatility (ann.) | 6.5% | 67.5% |
| Beta vs S&P 500 | 0.04 | 0.59 |
| Max drawdown (3Y) | -6.9% | -89.4% |
| Market cap | – | $1.7B |
| P/E (trailing) | – | – |
| Dividend yield | 3.96% | 0.00% |
| Expense ratio | 0.15% | – |
| Assets under management | $47.2B | – |
| Sector / category | ETF · Bonds | US Listed |
On the fund side, IEF sits in the Long Government category at iShares, with $47.2B under management, a 0.15% expense ratio, a 3.96% trailing dividend yield.
Year-by-year returns
| Year | IEF | KOS |
|---|---|---|
| 2022 | -15.2% | +83.8% |
| 2023 | +3.6% | +5.5% |
| 2024 | -0.6% | -49.0% |
| 2025 | +8.0% | -73.4% |
| 2026 | -0.8% | +215.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IEF and KOS good diversifiers for each other?
By historical standards, yes. A correlation of -0.27 means the two rarely move for the same reasons.
FAQ
What is the correlation between IEF and KOS?
As of 2026-08-27, the correlation of weekly returns between IEF and KOS is -0.27 over 3 years, -0.38 over 1 year and -0.19 over 5 years.
Is KOS a good diversifier for IEF?
By historical standards, yes. A correlation of -0.27 means the two rarely move for the same reasons.
What does a correlation of -0.27 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/ief-vs-kos.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/ief-vs-kos/)
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Related comparisons
Hubs: IEF correlations · KOS correlations
