RMBS vs SOXX: Correlation
How closely do Rambus, Inc. (RMBS) and iShares Semiconductor ETF (SOXX) trade together? Their weekly returns over three years give a correlation of 0.70, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are RMBS and SOXX?
Across a 3-year window, the weekly returns of RMBS and SOXX correlate at 0.70, strong. The relationship has been stable: the 1-year correlation (0.67) sits close to the 3-year figure. Stretching to 5 years gives 0.68, with an annualized covariance of 1443.7 %².
In RMBS's tracked universe of 12 assets, SOXX sits right near the top at #1. Their recent paths diverged sharply: over the last 12 months SOXX outperformed by 88.6 percentage points (+21.4% for RMBS against +110.0% for SOXX). Risk is not evenly split, since RMBS carries 1.7 times the volatility of the other side.
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.
RMBS vs SOXX: side by side
| RMBS (Rambus, Inc.) | SOXX (iShares Semiconductor ETF) | |
|---|---|---|
| 1-year return | +21.4% | +110.0% |
| 5-year return | +269.6% | +247.5% |
| Volatility (ann.) | 59.1% | 35.2% |
| Beta vs S&P 500 | 2.22 | 1.93 |
| Max drawdown (3Y) | -51.5% | -41.4% |
| Market cap | $9.9B | – |
| P/E (trailing) | 41.4 | – |
| Dividend yield | 0.00% | 0.29% |
| Expense ratio | – | 0.33% |
| Assets under management | – | $44.7B |
| Sector / category | US Listed | ETF · Thematic |
On the fund side, SOXX sits in the Technology category at iShares, with $44.7B under management, 30 holdings, a 0.33% expense ratio, a 0.29% trailing dividend yield.
Year-by-year returns
| Year | RMBS | SOXX |
|---|---|---|
| 2022 | +21.9% | -35.1% |
| 2023 | +90.5% | +67.1% |
| 2024 | -22.5% | +12.9% |
| 2025 | +73.8% | +40.7% |
| 2026 | -0.8% | +74.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
RMBS represents 0.54% of SOXX's portfolio, so part of any move in SOXX is RMBS itself, and the correlation between them is partly mechanical.
Are RMBS and SOXX good diversifiers for each other?
Somewhat, no more. With 0.70 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between RMBS and SOXX?
As of 2026-08-27, the correlation of weekly returns between RMBS and SOXX is 0.70 over 3 years, 0.67 over 1 year and 0.68 over 5 years.
Is SOXX a good diversifier for RMBS?
Somewhat, no more. With 0.70 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.70 mean?
On the −1 to +1 scale, 0.70 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/rmbs-vs-soxx.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/rmbs-vs-soxx/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: RMBS correlations · SOXX correlations
