SPY vs ULBI: Correlation
How closely do SPDR S&P 500 ETF Trust (SPY) and Ultralife Corporation (ULBI) trade together? Their weekly returns over three years give a correlation of 0.42, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPY and ULBI?
On 3 years of weekly data the SPY/ULBI correlation comes out at 0.42, moderate. Recent behaviour matches the longer record: 0.34 over 1 year against 0.42 over 3. The 5-year figure is 0.27, and annualized covariance runs at 363.0 %².
Among the 4755 assets we track against SPY, ULBI ranks #998 by 3-year correlation. Correlation aside, the last 12 months split them widely, with SPY ahead by 26.3 points (+20.6% versus -5.7%). One caveat on sizing: ULBI is 4.1 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 ULBI: side by side
| SPY (SPDR S&P 500 ETF Trust) | ULBI (Ultralife Corporation) | |
|---|---|---|
| 1-year return | +20.6% | -5.7% |
| 5-year return | +82.4% | -19.1% |
| Volatility (ann.) | 14.5% | 59.1% |
| Beta vs S&P 500 | 1.00 | 1.74 |
| Max drawdown (3Y) | -18.8% | -68.8% |
| 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 |
SPY, State Street Investment Management's Large Blend fund, carries $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | SPY | ULBI |
|---|---|---|
| 2022 | -18.2% | -36.1% |
| 2023 | +26.2% | +76.7% |
| 2024 | +24.9% | +9.2% |
| 2025 | +17.7% | -23.2% |
| 2026 | +13.7% | +13.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPY and ULBI good diversifiers for each other?
A fair diversifier. At 0.42, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between SPY and ULBI?
Using weekly returns as of 2026-08-27: 0.42 over 3 years, with 0.34 over the last year and 0.27 over 5 years.
Is ULBI a good diversifier for SPY?
A fair diversifier. At 0.42, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.42 mean?
A reading of 0.42 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/spy-vs-ulbi.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/spy-vs-ulbi/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: SPY correlations · ULBI correlations
