SPY vs ZS: Correlation
How closely do SPDR S&P 500 ETF Trust (SPY) and Zscaler, Inc. (ZS) trade together? Their weekly returns over three years give a correlation of 0.46, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and ZS?
Across a 3-year window, the weekly returns of SPY and ZS correlate at 0.46, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.16 versus 0.46 over 3 years. Stretching to 5 years gives 0.55, with an annualized covariance of 306.8 %².
By 3-year correlation, ZS places #683 of the 4755 assets tracked against SPY. The last year tells two different stories: SPY led by 52.0 percentage points, +20.6% for SPY against -31.4% for ZS. Risk is not evenly split, since ZS carries 3.2 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 ZS: side by side
| SPY (SPDR S&P 500 ETF Trust) | ZS (Zscaler, Inc.) | |
|---|---|---|
| 1-year return | +20.6% | -31.4% |
| 5-year return | +82.4% | -32.7% |
| Volatility (ann.) | 14.5% | 45.7% |
| Beta vs S&P 500 | 1.00 | 1.47 |
| Max drawdown (3Y) | -18.8% | -64.9% |
| Market cap | – | $30.3B |
| 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 | ZS |
|---|---|---|
| 2022 | -18.2% | -65.2% |
| 2023 | +26.2% | +98.0% |
| 2024 | +24.9% | -18.6% |
| 2025 | +17.7% | +24.7% |
| 2026 | +13.7% | -16.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and ZS good diversifiers for each other?
Reasonably. At 0.46, SPY and ZS keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between SPY and ZS?
As of 2026-08-27, the correlation of weekly returns between SPY and ZS is 0.46 over 3 years, 0.16 over 1 year and 0.55 over 5 years.
Is ZS a good diversifier for SPY?
Reasonably. At 0.46, SPY and ZS keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.46 mean?
On the −1 to +1 scale, 0.46 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/spy-vs-zs.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/spy-vs-zs/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: SPY correlations · ZS correlations
