Theta - Financial definition Financial acronyms The entire acronym collection of this site is now also available offline with this new app for iPhone and iPad. Tags: options valuation and pricing Concise definition of the term theta Measures the sensitivity of the value of an option to the passage of time. Additional information related to this definition Definitions of related terms Delta • Gamma • Option • Rho • Vega Formulas related to this definition Theta of a call option • Theta of a put option Browse the financial glossary in alpabetical order # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z