PLSE vs SPY: Correlation
How closely do Pulse Biosciences, Inc (PLSE) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.26, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are PLSE and SPY?
Over the past 3 years, PLSE and SPY moved with a correlation of 0.26, which is weak. The link has loosened recently: the 1-year correlation (0.09) runs below the 3-year figure (0.26). Over 5 years the correlation is 0.21, and the annualized covariance of weekly returns is 323.6 %².
SPY is close to the least connected end of PLSE's tracked universe, ranking #7 of 11. Their recent paths diverged sharply: over the last 12 months PLSE outperformed by 185.8 percentage points (+206.4% for PLSE against +20.6% for SPY). Risk is not evenly split, since PLSE carries 6.0 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.
PLSE vs SPY: side by side
| PLSE (Pulse Biosciences, Inc) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +206.4% | +20.6% |
| 5-year return | +82.4% | +82.4% |
| Volatility (ann.) | 86.6% | 14.5% |
| Beta vs S&P 500 | 1.55 | 1.00 |
| Max drawdown (3Y) | -48.5% | -18.8% |
| Market cap | $3.5B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | ETF · US Large Cap |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | PLSE | SPY |
|---|---|---|
| 2022 | -81.3% | -18.2% |
| 2023 | +341.9% | +26.2% |
| 2024 | +42.2% | +24.9% |
| 2025 | -21.1% | +17.7% |
| 2026 | +253.7% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are PLSE and SPY good diversifiers for each other?
Reasonably. At 0.26, PLSE and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between PLSE and SPY?
The PLSE/SPY correlation stands at 0.26 on a 3-year window (1 year: 0.09, 5 years: 0.21), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for PLSE?
Reasonably. At 0.26, PLSE and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.26 mean?
On the −1 to +1 scale, 0.26 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.
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Related comparisons
Hubs: PLSE correlations · SPY correlations
