&gt; Also, the timing is only applicable to European options which expire on a specific date. American options have no expiration date!<p>Umm, American options still have an expiry date.  They can be called earlier than their expiration date, though unless there is a dividend to be paid, its never advantageous to do so.<p>But American options absolutely have an expiration date.  They wouldn&#x27;t make sense otherwise.<p>I mean at price would you sell someone a put or a call if they could wait forever to exercise it?<p>No matter what implied vol you put on the underlying, you would still have to price it at infinity wouldn&#x27;t you?