Option Theta & NPV

Posted by newbie73 on Sep 19, 2007; 10:07pm
URL: http://quantlib.414.s1.nabble.com/Option-Theta-NPV-tp1396.html

When accessing an Option's Theta, how should I interpret this number?

option.NPV() --> 2.18
option.theta() --> -2.26

My understanding of Theta is that it is the change per some set period of time in the value of the option.  How can abs(theta) > NPV()???