IEX vs RSP: Correlation
IDEX Corporation (IEX) and Invesco S&P 500 Equal Weight ETF (RSP) show a strong relationship: their 3-year correlation of weekly returns is 0.70.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IEX and RSP?
On 3 years of weekly data the IEX/RSP correlation comes out at 0.70, strong. Lately the two have drifted apart, with the 1-year correlation at 0.57 versus 0.70 over 3 years. The 5-year figure is 0.69, and annualized covariance runs at 214.6 %².
Within IEX's tracked universe of 40 assets, RSP comes in at #5 by 3-year correlation. The last year tells two different stories: IEX led by 23.8 percentage points, +43.0% for IEX against +19.2% for RSP. The rolling one-year correlation stayed in a tight band between 0.57 and 0.78 over the past three years, which points to a structural rather than episodic relationship. Note the risk asymmetry: IEX runs 1.8 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
IEX vs RSP: side by side
| IEX (IDEX Corporation) | RSP (Invesco S&P 500 Equal Weight ETF) | |
|---|---|---|
| 1-year return | +43.0% | +19.2% |
| 5-year return | +10.5% | +53.9% |
| Volatility (ann.) | 23.3% | 13.2% |
| Beta vs S&P 500 | 0.89 | 0.77 |
| Max drawdown (3Y) | -34.6% | -17.8% |
| Market cap | $17.2B | – |
| P/E (trailing) | 33.8 | – |
| Dividend yield | 1.23% | 1.49% |
| Expense ratio | – | 0.20% |
| Assets under management | – | $97.3B |
| Sector / category | Industrials | ETF · US Large Cap |
On the fund side, RSP sits in the Large Blend category at Invesco, with $97.3B under management, 505 holdings, a 0.20% expense ratio, a 1.49% trailing dividend yield.
Year-by-year returns
| Year | IEX | RSP |
|---|---|---|
| 2022 | -2.2% | -11.6% |
| 2023 | -3.8% | +13.7% |
| 2024 | -2.4% | +12.8% |
| 2025 | -13.7% | +11.2% |
| 2026 | +32.9% | +16.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that RSP holds IEX at a 0.2% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are IEX and RSP good diversifiers for each other?
Only partially. A correlation of 0.70 means IEX and RSP share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between IEX and RSP?
The IEX/RSP correlation stands at 0.70 on a 3-year window (1 year: 0.57, 5 years: 0.69), computed from weekly returns as of 2026-08-27.
Is RSP a good diversifier for IEX?
Only partially. A correlation of 0.70 means IEX and RSP share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.70 mean?
A reading of 0.70 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/iex-vs-rsp.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/iex-vs-rsp/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: IEX correlations · RSP correlations
