SPY vs TAC: Correlation
SPDR S&P 500 ETF Trust (SPY) and TransAlta Corporation (TAC) 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 TAC?
Across a 3-year window, the weekly returns of SPY and TAC correlate at 0.34, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.24 versus 0.34 over 3 years. Stretching to 5 years gives 0.35, with an annualized covariance of 175.8 %².
Within SPY's tracked universe of 4755 assets, TAC comes in at #1808 by 3-year correlation. The last year tells two different stories: SPY led by 16.3 percentage points, +20.6% for SPY against +4.3% for TAC. One caveat on sizing: TAC is 2.5 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.
SPY vs TAC: side by side
| SPY (SPDR S&P 500 ETF Trust) | TAC (TransAlta Corporation) | |
|---|---|---|
| 1-year return | +20.6% | +4.3% |
| 5-year return | +82.4% | +36.9% |
| Volatility (ann.) | 14.5% | 36.2% |
| Beta vs S&P 500 | 1.00 | 0.84 |
| Max drawdown (3Y) | -18.8% | -43.3% |
| Market cap | – | $4.0B |
| P/E (trailing) | – | – |
| Dividend yield | 1.01% | 2.10% |
| 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 | TAC |
|---|---|---|
| 2022 | -18.2% | -18.0% |
| 2023 | +26.2% | -5.6% |
| 2024 | +24.9% | +74.0% |
| 2025 | +17.7% | -9.5% |
| 2026 | +13.7% | -0.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and TAC 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 TAC?
As of 2026-08-27, the correlation of weekly returns between SPY and TAC is 0.34 over 3 years, 0.24 over 1 year and 0.35 over 5 years.
Is TAC 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?
On the −1 to +1 scale, 0.34 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-tac.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/spy-vs-tac/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: SPY correlations · TAC correlations
