SPY vs TCMD: Correlation
How closely do SPDR S&P 500 ETF Trust (SPY) and Tactile Systems Technology, Inc. (TCMD) trade together? Their weekly returns over three years give a correlation of 0.20, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and TCMD?
Across a 3-year window, the weekly returns of SPY and TCMD correlate at 0.20, weak. The past 12 months show a weaker link (-0.03) than the 3-year average (0.20). Stretching to 5 years gives 0.33, with an annualized covariance of 182.3 %².
Within SPY's tracked universe of 4755 assets, TCMD comes in at #3287 by 3-year correlation. The last year tells two different stories: TCMD led by 55.1 percentage points, +20.6% for SPY against +75.7% for TCMD. One caveat on sizing: TCMD is 4.4 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 TCMD: side by side
| SPY (SPDR S&P 500 ETF Trust) | TCMD (Tactile Systems Technology, Inc.) | |
|---|---|---|
| 1-year return | +20.6% | +75.7% |
| 5-year return | +82.4% | -47.2% |
| Volatility (ann.) | 14.5% | 63.6% |
| Beta vs S&P 500 | 1.00 | 0.87 |
| Max drawdown (3Y) | -18.8% | -51.8% |
| Market cap | – | $0.5B |
| P/E (trailing) | – | 22.0 |
| Dividend yield | 1.01% | 0.00% |
| Expense ratio | 0.09% | – |
| Assets under management | $795.3B | – |
| Sector / category | ETF · US Large Cap | US Listed |
On the fund side, SPY sits in the Large Blend category at State Street Investment Management, with $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | SPY | TCMD |
|---|---|---|
| 2022 | -18.2% | -39.7% |
| 2023 | +26.2% | +24.6% |
| 2024 | +24.9% | +19.8% |
| 2025 | +17.7% | +69.3% |
| 2026 | +13.7% | -20.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and TCMD good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.20 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between SPY and TCMD?
The SPY/TCMD correlation stands at 0.20 on a 3-year window (1 year: -0.03, 5 years: 0.33), computed from weekly returns as of 2026-08-27.
Is TCMD a good diversifier for SPY?
Yes, to a useful degree: a correlation of 0.20 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.20 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/spy-vs-tcmd.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/spy-vs-tcmd/)
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Related comparisons
Hubs: SPY correlations · TCMD correlations
