BLIN vs SPY: Correlation
Bridgeline Digital, Inc. (BLIN) and SPDR S&P 500 ETF Trust (SPY) show a near-zero relationship: their 3-year correlation of weekly returns is 0.09.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BLIN and SPY?
Across a 3-year window, the weekly returns of BLIN and SPY correlate at 0.09, near zero, meaning they move largely independently. The past 12 months show a tighter link (0.25) than the 3-year average (0.09). Stretching to 5 years gives 0.20, with an annualized covariance of 74.8 %².
SPY is close to the least connected end of BLIN's tracked universe, ranking #7 of 10. Correlation aside, the last 12 months split them widely, with SPY ahead by 47.5 points (-26.9% versus +20.6%). Note the risk asymmetry: BLIN runs 4.1 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.
BLIN vs SPY: side by side
| BLIN (Bridgeline Digital, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -26.9% | +20.6% |
| 5-year return | -81.9% | +82.4% |
| Volatility (ann.) | 60.1% | 14.5% |
| Beta vs S&P 500 | 0.36 | 1.00 |
| Max drawdown (3Y) | -70.2% | -18.8% |
| Market cap | – | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | 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 | BLIN | SPY |
|---|---|---|
| 2022 | -53.5% | -18.2% |
| 2023 | -17.1% | +26.2% |
| 2024 | +81.6% | +24.9% |
| 2025 | -47.5% | +17.7% |
| 2026 | +19.0% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BLIN and SPY good diversifiers for each other?
Yes: at 0.09, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between BLIN and SPY?
As of 2026-08-27, the correlation of weekly returns between BLIN and SPY is 0.09 over 3 years, 0.25 over 1 year and 0.20 over 5 years.
Is SPY a good diversifier for BLIN?
Yes: at 0.09, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of 0.09 mean?
On the −1 to +1 scale, 0.09 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: BLIN correlations · SPY correlations
