BILL vs SPY: Correlation
Measured on weekly returns over the past three years, BILL Holdings, Inc. (BILL) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.32, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BILL and SPY?
Over the past 3 years, BILL and SPY moved with a correlation of 0.32, which is moderate. The relationship has been stable: the 1-year correlation (0.32) sits close to the 3-year figure. Over 5 years the correlation is 0.47, and the annualized covariance of weekly returns is 262.3 %².
Within BILL's tracked universe of 13 assets, SPY comes in at #7 by 3-year correlation. Neither side won the trailing year by much: +17.4% against +20.6%. Note the risk asymmetry: BILL runs 3.9 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.
BILL vs SPY: side by side
| BILL (BILL Holdings, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +17.4% | +20.6% |
| 5-year return | -82.7% | +82.4% |
| Volatility (ann.) | 57.0% | 14.5% |
| Beta vs S&P 500 | 1.26 | 1.00 |
| Max drawdown (3Y) | -73.0% | -18.8% |
| Market cap | $4.9B | – |
| 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 | BILL | SPY |
|---|---|---|
| 2022 | -56.3% | -18.2% |
| 2023 | -25.1% | +26.2% |
| 2024 | +3.8% | +24.9% |
| 2025 | -35.6% | +17.7% |
| 2026 | -10.4% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BILL and SPY good diversifiers for each other?
A fair diversifier. At 0.32, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between BILL and SPY?
As of 2026-08-27, the correlation of weekly returns between BILL and SPY is 0.32 over 3 years, 0.32 over 1 year and 0.47 over 5 years.
Is SPY a good diversifier for BILL?
A fair diversifier. At 0.32, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.32 mean?
On the −1 to +1 scale, 0.32 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: BILL correlations · SPY correlations
