AP vs MLSS: Correlation
How closely do Ampco-Pittsburgh Corporation (AP) and Milestone Scientific, Inc. (MLSS) trade together? Their weekly returns over three years give a correlation of 0.35, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AP and MLSS?
On 3 years of weekly data the AP/MLSS correlation comes out at 0.35, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.10 versus 0.35 over 3 years. The 5-year figure is 0.26, and annualized covariance runs at 2807.9 %².
Among the 14 assets we track against AP, MLSS ranks #9 by 3-year correlation. Correlation aside, the last 12 months split them widely, with AP ahead by 248.4 points (+232.6% versus -15.8%).
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.
AP vs MLSS: side by side
| AP (Ampco-Pittsburgh Corporation) | MLSS (Milestone Scientific, Inc.) | |
|---|---|---|
| 1-year return | +232.6% | -15.8% |
| 5-year return | +90.5% | -72.6% |
| Volatility (ann.) | 94.5% | 84.1% |
| Beta vs S&P 500 | 1.63 | 0.81 |
| Max drawdown (3Y) | -77.6% | -81.2% |
| Market cap | $0.2B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | AP | MLSS |
|---|---|---|
| 2022 | -49.8% | -76.7% |
| 2023 | +8.8% | +43.8% |
| 2024 | -23.4% | +39.1% |
| 2025 | +155.0% | -71.9% |
| 2026 | +72.2% | +87.0% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AP and MLSS good diversifiers for each other?
Reasonably. At 0.35, AP and MLSS keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between AP and MLSS?
The AP/MLSS correlation stands at 0.35 on a 3-year window (1 year: 0.10, 5 years: 0.26), computed from weekly returns as of 2026-08-27.
Is MLSS a good diversifier for AP?
Reasonably. At 0.35, AP and MLSS keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.35 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/ap-vs-mlss.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/ap-vs-mlss/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: AP correlations · MLSS correlations
