BCAB vs RARE: Correlation
Measured on weekly returns over the past three years, BioAtla, Inc. (BCAB) and Ultragenyx Pharmaceutical Inc. (RARE) carry a correlation of 0.45, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BCAB and RARE?
Over the past 3 years, BCAB and RARE moved with a correlation of 0.45, which is moderate. Little has changed lately, as the 1-year reading of 0.41 lands near the 3-year figure. Over 5 years the correlation is 0.38, and the annualized covariance of weekly returns is 2724.3 %².
By 3-year correlation, RARE places #5 of the 11 assets tracked against BCAB. Their recent paths diverged sharply: over the last 12 months RARE outperformed by 73.3 percentage points (-86.0% for BCAB against -12.7% for RARE). One caveat on sizing: BCAB is 2.3 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.
BCAB vs RARE: side by side
| BCAB (BioAtla, Inc.) | RARE (Ultragenyx Pharmaceutical Inc.) | |
|---|---|---|
| 1-year return | -86.0% | -12.7% |
| 5-year return | -99.8% | -72.6% |
| Volatility (ann.) | 119.3% | 51.1% |
| Beta vs S&P 500 | 2.75 | 1.38 |
| Max drawdown (3Y) | -98.4% | -68.8% |
| Market cap | – | $2.6B |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | BCAB | RARE |
|---|---|---|
| 2022 | -58.0% | -44.9% |
| 2023 | -70.2% | +3.2% |
| 2024 | -76.0% | -12.0% |
| 2025 | -3.9% | -45.3% |
| 2026 | -88.9% | +14.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BCAB and RARE good diversifiers for each other?
Reasonably. At 0.45, BCAB and RARE keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between BCAB and RARE?
The BCAB/RARE correlation stands at 0.45 on a 3-year window (1 year: 0.41, 5 years: 0.38), computed from weekly returns as of 2026-08-27.
Is RARE a good diversifier for BCAB?
Reasonably. At 0.45, BCAB and RARE keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.45 mean?
On the −1 to +1 scale, 0.45 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/bcab-vs-rare.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/bcab-vs-rare/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: BCAB correlations · RARE correlations
