beta

Beta (UK: /ˈbiːtə/, US: /ˈbeɪtə/; uppercase. Β, lowercase. β, or cursive. ϐ; Ancient Greek: βῆτα, romanized: bē̂ta or Greek: βήτα, romanized: víta) is the second letter of the Greek alphabet.

In finance, the beta (β or beta coefficient) of an investment is a measure of the risk arising from exposure to general market movements as opposed to idiosyncratic factors. The market portfolio of all investable assets has a beta of exactly 1. A beta below 1 can indicate either an investment with lower...