PRME vs RLYB: Correlation
How closely do Prime Medicine, Inc. (PRME) and Rallybio Corporation (RLYB) trade together? Their weekly returns over three years give a correlation of 0.36, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are PRME and RLYB?
Over the past 3 years, PRME and RLYB moved with a correlation of 0.36, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.15 versus 0.36 over 3 years. Over 5 years the correlation is 0.36, and the annualized covariance of weekly returns is 3566.6 %².
RLYB is close to the least connected end of PRME's tracked universe, ranking #15 of 18. The last year tells two different stories: RLYB led by 249.0 percentage points, +6.1% for PRME against +255.1% for RLYB.
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.
PRME vs RLYB: side by side
| PRME (Prime Medicine, Inc.) | RLYB (Rallybio Corporation) | |
|---|---|---|
| 1-year return | +6.1% | +255.1% |
| 5-year return | n/a | -83.7% |
| Volatility (ann.) | 98.7% | 99.0% |
| Beta vs S&P 500 | 2.97 | 0.78 |
| Max drawdown (3Y) | -91.4% | -95.5% |
| Market cap | $0.7B | $0.1B |
| P/E (trailing) | – | 2.1 |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | PRME | RLYB |
|---|---|---|
| 2022 | – | -31.1% |
| 2023 | -52.3% | -63.6% |
| 2024 | -67.0% | -59.8% |
| 2025 | +18.8% | -28.5% |
| 2026 | +4.9% | +205.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are PRME and RLYB good diversifiers for each other?
Reasonably. At 0.36, PRME and RLYB keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between PRME and RLYB?
Using weekly returns as of 2026-08-27: 0.36 over 3 years, with 0.15 over the last year and 0.36 over 5 years.
Is RLYB a good diversifier for PRME?
Reasonably. At 0.36, PRME and RLYB keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.36 mean?
On the −1 to +1 scale, 0.36 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/prme-vs-rlyb.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/prme-vs-rlyb/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: PRME correlations · RLYB correlations
