28300 call will settle at 20
28200 call will settle at 120
As these are expired ITM, high STT will be there which is already discounted in closing price. Also I believe NSE has not yet updated settlement price yet at that time.
I have been wonder about this for a while now too. have not really gotten a satisfactory answer from various searches. the NSE site has this to say.
What I “think” it is, is that say OI is 200,000 @ rs, 2.00 . A person comes in and for what ever reason sells one lot, (say a lot is x1000) at Re. 1. Then it wont be a fair price for rest of the holders, in this case 199,000 OI holders to lose half their portfolio value due to a single trade.