Is there certain logic to how the option are priced on expiration day? Give an example, last friday I had some nflx 165 weekly calls and was monitoring their behavior all day at work with the iphone, they kept their value for much longer than i expected. At around 2PM, the option was ~$1-2 otm, but it still had a premium of 40 cents. I suppose that's normal given the high price of the underlying. I guess the question is are there some formula or consistency in determining the price of options on expiration day, if they are slightly OTM or ATM? Is it still the same formula based off iv?