Comment on STT Trap - Options Expiry - NSE BSE MCX-SX
If you keep holding the 6200 PE and don’t square off, after the market closing on expiry your option is exercised. Since it is exercised, it is considered as a delivery trade and STT is charged on the entire contract value ( 0.01% of around 3lks = Rs 300). If you had sold it in the market at 200 you would have paid an STT only on premium ( 0.017% of Rs 10,000 = Rs 1.7).
So you end up paying a lot more STT.