Hello mastermind007,
We agree with you that as long as the funds are available in client's account it should be allowed.
However, if you refer to the scenario 2 mentioned in our knowledge base article
How is the STT computed in case an in-the-money option contract expires?, you'll notice that the STT alone on a Rs 100 option comes out to Rs 381. Trading software does not have the capability to block premium+STT as a margin.
Moreover, on the expiry day due to the high STT priced in, some of the in the money options may seem attractively priced and seem like an assure way to make a profit. This has mislead many of our clients into buying them even at times like 3:28 pm when we can hardly give them any alert/warning. They have lost huge amounts due to this.
Though we do send messages and emails to our clients who have an in-the-money or at-the-money positions, it becomes very difficult to manually warn everyone if they are to place a trade towards the end of the day.
In our view losses in buying-selling decisions are very different from losses due to lack of information about the tax structure.
Also, we are blocking only overnight positions on the buy side in options to avoid our clients losing money due to the high STT. Sell side is still open and intraday positions also open. Most of the strategies can still be implemented with this blocking.
If you have a better suggestion which takes care of the interest of our clients you are welcome to share the same with us.