Börsenlexikon: Theta

The theta is the eighth letter of the Greek alphabet and, according to the Milesian principle, has a numerical value of 9. In the case of warrants, this ratio measures the time value decay of an option. The theta indicates how much a warrant will lose in value over a given period of time, all other factors remaining equal (ceteris paribus). In practice, the percentage decline in value per week is compared.