SPY vs TGEN: Correlation
Measured on weekly returns over the past three years, SPDR S&P 500 ETF Trust (SPY) and Tecogen Inc. (TGEN) carry a correlation of 0.26, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and TGEN?
Over the past 3 years, SPY and TGEN moved with a correlation of 0.26, which is weak. The past 12 months show a tighter link (0.47) than the 3-year average (0.26). Over 5 years the correlation is 0.28, and the annualized covariance of weekly returns is 400.4 %².
Within SPY's tracked universe of 4755 assets, TGEN comes in at #2675 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 80.4 percentage points (+20.6% for SPY against -59.8% for TGEN). Risk is not evenly split, since TGEN carries 7.3 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 TGEN: side by side
| SPY (SPDR S&P 500 ETF Trust) | TGEN (Tecogen Inc.) | |
|---|---|---|
| 1-year return | +20.6% | -59.8% |
| 5-year return | +82.4% | +76.1% |
| Volatility (ann.) | 14.5% | 106.2% |
| Beta vs S&P 500 | 1.00 | 1.92 |
| Max drawdown (3Y) | -18.8% | -83.4% |
| 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 |
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 | TGEN |
|---|---|---|
| 2022 | -18.2% | +4.2% |
| 2023 | +26.2% | -35.2% |
| 2024 | +24.9% | +80.9% |
| 2025 | +17.7% | +237.2% |
| 2026 | +13.7% | -35.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and TGEN good diversifiers for each other?
A fair diversifier. At 0.26, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between SPY and TGEN?
As of 2026-08-27, the correlation of weekly returns between SPY and TGEN is 0.26 over 3 years, 0.47 over 1 year and 0.28 over 5 years.
Is TGEN a good diversifier for SPY?
A fair diversifier. At 0.26, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.26 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-tgen.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/spy-vs-tgen/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: SPY correlations · TGEN correlations
