: 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.
Volatility (finance) - Mathematical definition. 1  For any fund that evolves randomly with time, the square of volatility is the variance of the sum of infinitely many instantaneous rates of return, each taken over the nonoverlapping, infinitesimal periods that make up a single unit of time.