ISPC vs SFBC: Correlation
Measured on weekly returns over the past three years, iSpecimen Inc. (ISPC) and Sound Financial Bancorp, Inc. (SFBC) carry a correlation of -0.26, a negative link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ISPC and SFBC?
On 3 years of weekly data the ISPC/SFBC correlation comes out at -0.26, negative, meaning they tend to move in opposite directions. Little has changed lately, as the 1-year reading of -0.34 lands near the 3-year figure. The 5-year figure is -0.15, and annualized covariance runs at -708.8 %².
Out of 15 assets tracked against ISPC, SFBC lands near the bottom at #15. The last year tells two different stories: SFBC led by 95.0 percentage points, -94.6% for ISPC against +0.4% for SFBC. One caveat on sizing: ISPC is 5.4 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.
ISPC vs SFBC: side by side
| ISPC (iSpecimen Inc.) | SFBC (Sound Financial Bancorp, Inc.) | |
|---|---|---|
| 1-year return | -94.6% | +0.4% |
| 5-year return | -100.0% | +19.0% |
| Volatility (ann.) | 121.8% | 22.4% |
| Beta vs S&P 500 | 0.67 | 0.17 |
| Max drawdown (3Y) | -99.8% | -24.7% |
| Market cap | – | $0.1B |
| P/E (trailing) | – | 15.2 |
| Dividend yield | 0.00% | 1.69% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | ISPC | SFBC |
|---|---|---|
| 2022 | -82.4% | -9.0% |
| 2023 | -63.6% | +1.3% |
| 2024 | -73.5% | +37.4% |
| 2025 | -90.2% | -15.8% |
| 2026 | -84.6% | +10.0% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ISPC and SFBC good diversifiers for each other?
Yes: at -0.26, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between ISPC and SFBC?
The ISPC/SFBC correlation stands at -0.26 on a 3-year window (1 year: -0.34, 5 years: -0.15), computed from weekly returns as of 2026-08-27.
Is SFBC a good diversifier for ISPC?
Yes: at -0.26, the two have gone their own ways historically, which is what genuine diversification looks like.
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/ispc-vs-sfbc.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/ispc-vs-sfbc/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ISPC correlations · SFBC correlations
