AIFF vs WST: Correlation
Firefly Neuroscience, Inc. (AIFF) and West Pharmaceutical Services (WST) show a negative relationship: their 3-year correlation of weekly returns is -0.22.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AIFF and WST?
Across a 3-year window, the weekly returns of AIFF and WST correlate at -0.22, negative, meaning they tend to move in opposite directions. Lately the two have moved closer together, with the 1-year correlation at -0.03 versus -0.22 over 3 years. Stretching to 5 years gives -0.09, with an annualized covariance of -1626.9 %².
WST is close to the least connected end of AIFF's tracked universe, ranking #13 of 15. Correlation aside, the last 12 months split them widely, with WST ahead by 100.0 points (-58.9% versus +41.1%). Note the risk asymmetry: AIFF runs 4.9 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.
AIFF vs WST: side by side
| AIFF (Firefly Neuroscience, Inc.) | WST (West Pharmaceutical Services) | |
|---|---|---|
| 1-year return | -58.9% | +41.1% |
| 5-year return | -98.8% | -22.4% |
| Volatility (ann.) | 190.4% | 38.6% |
| Beta vs S&P 500 | 1.78 | 0.86 |
| Max drawdown (3Y) | -95.9% | -53.8% |
| Market cap | – | $24.4B |
| P/E (trailing) | – | 44.8 |
| Dividend yield | 0.00% | 0.25% |
| Sector / category | US Listed | Health Care |
Year-by-year returns
| Year | AIFF | WST |
|---|---|---|
| 2022 | -90.3% | -49.7% |
| 2023 | -64.8% | +50.0% |
| 2024 | -47.7% | -6.8% |
| 2025 | -66.8% | -15.7% |
| 2026 | +22.7% | +26.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AIFF and WST good diversifiers for each other?
By historical standards, yes. A correlation of -0.22 means the two rarely move for the same reasons.
FAQ
What is the correlation between AIFF and WST?
Using weekly returns as of 2026-08-27: -0.22 over 3 years, with -0.03 over the last year and -0.09 over 5 years.
Is WST a good diversifier for AIFF?
By historical standards, yes. A correlation of -0.22 means the two rarely move for the same reasons.
What does a correlation of -0.22 mean?
On the −1 to +1 scale, -0.22 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.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/aiff-vs-wst.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/aiff-vs-wst/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: AIFF correlations · WST correlations
