SPY vs SSTI: Correlation
SPDR S&P 500 ETF Trust (SPY) and SoundThinking, Inc. (SSTI) show a moderate relationship: their 3-year correlation of weekly returns is 0.34.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and SSTI?
Across a 3-year window, the weekly returns of SPY and SSTI correlate at 0.34, moderate. The relationship has been stable: the 1-year correlation (0.27) sits close to the 3-year figure. Stretching to 5 years gives 0.31, with an annualized covariance of 261.5 %².
By 3-year correlation, SSTI places #1805 of the 4755 assets tracked against SPY. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 69.9 percentage points (+20.6% for SPY against -49.3% for SSTI). Risk is not evenly split, since SSTI carries 3.7 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.
SPY vs SSTI: side by side
| SPY (SPDR S&P 500 ETF Trust) | SSTI (SoundThinking, Inc.) | |
|---|---|---|
| 1-year return | +20.6% | -49.3% |
| 5-year return | +82.4% | -83.7% |
| Volatility (ann.) | 14.5% | 53.5% |
| Beta vs S&P 500 | 1.00 | 1.25 |
| Max drawdown (3Y) | -18.8% | -78.3% |
| Market cap | – | $0.1B |
| P/E (trailing) | – | – |
| Dividend yield | 1.01% | 0.00% |
| Expense ratio | 0.09% | – |
| Assets under management | $795.3B | – |
| Sector / category | ETF · US Large Cap | US Listed |
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 | SPY | SSTI |
|---|---|---|
| 2022 | -18.2% | +14.6% |
| 2023 | +26.2% | -24.5% |
| 2024 | +24.9% | -48.9% |
| 2025 | +17.7% | -38.5% |
| 2026 | +13.7% | -21.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and SSTI good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.34 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between SPY and SSTI?
As of 2026-08-27, the correlation of weekly returns between SPY and SSTI is 0.34 over 3 years, 0.27 over 1 year and 0.31 over 5 years.
Is SSTI a good diversifier for SPY?
Yes, to a useful degree: a correlation of 0.34 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.34 mean?
A reading of 0.34 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/spy-vs-ssti.json
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[](https://www.pairbook.io/pair/spy-vs-ssti/)
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Related comparisons
Hubs: SPY correlations · SSTI correlations
