PTGX vs XBI: Correlation
Protagonist Therapeutics, Inc. (PTGX) and SPDR S&P Biotech ETF (XBI) show a moderate relationship: their 3-year correlation of weekly returns is 0.47.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are PTGX and XBI?
Across a 3-year window, the weekly returns of PTGX and XBI correlate at 0.47, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.27 versus 0.47 over 3 years. Stretching to 5 years gives 0.33, with an annualized covariance of 684.9 %².
Few assets follow PTGX as closely as XBI, which ranks #1 of 11 tracked partners. Their recent paths diverged sharply: over the last 12 months PTGX outperformed by 56.2 percentage points (+143.4% for PTGX against +87.2% for XBI). One caveat on sizing: PTGX is 1.9 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.
PTGX vs XBI: side by side
| PTGX (Protagonist Therapeutics, Inc.) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +143.4% | +87.2% |
| 5-year return | +219.7% | +28.6% |
| Volatility (ann.) | 53.0% | 27.7% |
| Beta vs S&P 500 | 0.49 | 1.09 |
| Max drawdown (3Y) | -31.6% | -33.0% |
| Market cap | $9.7B | – |
| P/E (trailing) | 145.1 | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | PTGX | XBI |
|---|---|---|
| 2022 | -68.1% | -25.9% |
| 2023 | +110.2% | +7.6% |
| 2024 | +68.3% | +1.0% |
| 2025 | +126.3% | +35.9% |
| 2026 | +71.2% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are PTGX and XBI good diversifiers for each other?
Reasonably. At 0.47, PTGX and XBI keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between PTGX and XBI?
Using weekly returns as of 2026-08-27: 0.47 over 3 years, with 0.27 over the last year and 0.33 over 5 years.
Is XBI a good diversifier for PTGX?
Reasonably. At 0.47, PTGX and XBI keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.47 mean?
On the −1 to +1 scale, 0.47 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
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Embed this badge (it refreshes with the data), with attribution:
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Related comparisons
Hubs: PTGX correlations · XBI correlations
