: an informal form of a name. â Diminutives can be a shortened form of a name (such as âJenâ for âJenniferâ and âDickâ for âRichardâ) or a name with a diminutive suffix added to it (such as âBobbyâ for âBobâ).
The sensitivity of an option's market value relative to a change in the time to expiration. Theta is a measure of time decay and tends to grow larger as an option approaches expiration.
DEFINITION of 'Beta'. Beta is a measure of the volatility, or systematic risk, of a security or a portfolio in comparison to the market as a whole. Beta is used in the capital asset pricing model (CAPM), a model that calculates the expected return of an asset based on its beta and expected market returns.Also known as beta coefficient.. beta of less than 1 means that the security will be less volatile than the market. A beta of greater than 1 indicates that the security's price will be more volatile than the market. For example, if a stock's beta is 1.2, it's theoretically 20% more volatile than the market.