CERS vs RSP: Correlation
How closely do Cerus Corporation (CERS) and Invesco S&P 500 Equal Weight ETF (RSP) trade together? Their weekly returns over three years give a correlation of 0.54, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CERS and RSP?
Over the past 3 years, CERS and RSP moved with a correlation of 0.54, which is moderate. The past 12 months show a weaker link (0.38) than the 3-year average (0.54). Over 5 years the correlation is 0.49, and the annualized covariance of weekly returns is 506.2 %².
Within CERS's tracked universe of 10 assets, RSP comes in at #5 by 3-year correlation. Correlation aside, the last 12 months split them widely, with CERS ahead by 88.4 points (+107.6% versus +19.2%). Note the risk asymmetry: CERS runs 5.4 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.
CERS vs RSP: side by side
| CERS (Cerus Corporation) | RSP (Invesco S&P 500 Equal Weight ETF) | |
|---|---|---|
| 1-year return | +107.6% | +19.2% |
| 5-year return | -57.3% | +53.9% |
| Volatility (ann.) | 71.0% | 13.2% |
| Beta vs S&P 500 | 2.01 | 0.77 |
| Max drawdown (3Y) | -52.1% | -17.8% |
| Market cap | $0.5B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 1.49% |
| Expense ratio | – | 0.20% |
| Assets under management | – | $97.3B |
| Sector / category | US Listed | 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 | CERS | RSP |
|---|---|---|
| 2022 | -46.4% | -11.6% |
| 2023 | -40.8% | +13.7% |
| 2024 | -28.7% | +12.8% |
| 2025 | +33.8% | +11.2% |
| 2026 | +32.0% | +16.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CERS and RSP good diversifiers for each other?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between CERS and RSP?
Using weekly returns as of 2026-08-27: 0.54 over 3 years, with 0.38 over the last year and 0.49 over 5 years.
Is RSP a good diversifier for CERS?
To a limited degree. At 0.54 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.54 mean?
A reading of 0.54 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/cers-vs-rsp.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/cers-vs-rsp/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: CERS correlations · RSP correlations
