Beta
Beta > 1: more volatile than market. Beta < 1: less. Used in CAPM.
UK FTSE 100 is the typical benchmark.
Worked examples
Beta 1.5: stock moves 1.5× market.
Beta 0.5: stock moves half as much.
Frequently asked questions
How is it computed?
Covariance(stock, market) / variance(market). Typically over 36-60 months of returns.