PTC vs SPY: Correlation
How closely do PTC Inc. (PTC) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.51, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are PTC and SPY?
Over the past 3 years, PTC and SPY moved with a correlation of 0.51, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.34 versus 0.51 over 3 years. Over 5 years the correlation is 0.54, and the annualized covariance of weekly returns is 213.3 %².
By 3-year correlation, SPY places #16 of the 32 assets tracked against PTC. Correlation aside, the last 12 months split them widely, with SPY ahead by 47.2 points (-26.6% versus +20.6%). Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from 0.25 to 0.78. Note the risk asymmetry: PTC runs 2.0 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.
PTC vs SPY: side by side
| PTC (PTC Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -26.6% | +20.6% |
| 5-year return | +20.0% | +82.4% |
| Volatility (ann.) | 28.8% | 14.5% |
| Beta vs S&P 500 | 1.02 | 1.00 |
| Max drawdown (3Y) | -48.1% | -18.8% |
| Market cap | $17.2B | – |
| P/E (trailing) | 14.7 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Information Technology | 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 | PTC | SPY |
|---|---|---|
| 2022 | -0.9% | -18.2% |
| 2023 | +45.8% | +26.2% |
| 2024 | +5.1% | +24.9% |
| 2025 | -5.3% | +17.7% |
| 2026 | -8.8% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are PTC and SPY good diversifiers for each other?
To a limited degree. At 0.51 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between PTC and SPY?
The PTC/SPY correlation stands at 0.51 on a 3-year window (1 year: 0.34, 5 years: 0.54), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for PTC?
To a limited degree. At 0.51 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.51 mean?
On the −1 to +1 scale, 0.51 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: PTC correlations · SPY correlations
