What happens to short ITM options on expiry day


#1

Suppose I’ve shorted a CE/PE option going into expiry day, what will happen if it’s ITM? Like OTM option will it get squared-off automatically and I get to keep the premium?


#2

Theoretically yes but stt is huge in exercising options. Be aware of that


#3

Well, I’ve already sold the option hence there won’t/shouldn’t be any STT applicable like it is with short OTM options, right?