IWM vs RYTM: Correlation
iShares Russell 2000 ETF (IWM) and Rhythm Pharmaceuticals, Inc. (RYTM) show a moderate relationship: their 3-year correlation of weekly returns is 0.53.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IWM and RYTM?
On 3 years of weekly data the IWM/RYTM correlation comes out at 0.53, moderate. The link has loosened recently: the 1-year correlation (0.41) runs below the 3-year figure (0.53). The 5-year figure is 0.34, and annualized covariance runs at 609.7 %².
Within IWM's tracked universe of 320 assets, RYTM comes in at #197 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IWM outperformed by 18.4 percentage points (+28.4% for IWM against +10.0% for RYTM). One caveat on sizing: RYTM is 2.9 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.
IWM vs RYTM: side by side
| IWM (iShares Russell 2000 ETF) | RYTM (Rhythm Pharmaceuticals, Inc.) | |
|---|---|---|
| 1-year return | +28.4% | +10.0% |
| 5-year return | +41.5% | +785.4% |
| Volatility (ann.) | 19.8% | 58.4% |
| Beta vs S&P 500 | 1.06 | 1.92 |
| Max drawdown (3Y) | -27.5% | -35.5% |
| Market cap | – | $7.7B |
| P/E (trailing) | – | – |
| Dividend yield | 0.91% | 0.00% |
| Expense ratio | 0.19% | – |
| Assets under management | $80.1B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
IWM is a Small Blend fund from iShares: $80.1B under management, 1757 holdings, a 0.19% expense ratio, a 0.91% trailing dividend yield.
Year-by-year returns
| Year | IWM | RYTM |
|---|---|---|
| 2022 | -20.5% | +191.8% |
| 2023 | +16.8% | +57.9% |
| 2024 | +11.4% | +21.8% |
| 2025 | +12.7% | +91.2% |
| 2026 | +22.3% | +5.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.19% of IWM is RYTM itself, so the fund partly moves with the stock by construction.
Are IWM and RYTM good diversifiers for each other?
Only partially. A correlation of 0.53 means IWM and RYTM 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 IWM and RYTM?
The IWM/RYTM correlation stands at 0.53 on a 3-year window (1 year: 0.41, 5 years: 0.34), computed from weekly returns as of 2026-08-27.
Is RYTM a good diversifier for IWM?
Only partially. A correlation of 0.53 means IWM and RYTM share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.53 mean?
A reading of 0.53 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/iwm-vs-rytm.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/iwm-vs-rytm/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: IWM correlations · RYTM correlations
