Hi guys

I wanted to clarify a bit how orders are filled for options. From experience, I know that in-the-money and far-out-of-the-money options tick very seldom (but are quoted all the time).

Are the option fills calculated only on tick data (i.e. on option trades that really happened in the past) or are they executed on historically quoted bid/ask prices even if there was no trade at that particular option?

Thanks a lot!