Say I own 1 lakh shares of a company, bought at 15 rs, already in my demat account and sell it for 25 rs . What are the implications…do I need 20 percent margin to sell.this ? So I will need to have 20 percent of 25 lakhs? That is 5 lakhs lying in my trading account just to sell shares that I already own in my demat account . I’m confused.

Refer to this support article

Like how you can currently use stock sold to buy other stocks, the same will continue to be allowed from Sep 1st, 2020. By debiting your demat account and doing EPI to the exchanges by 7.30 PM on the same day as explained above, we can allow you to sell your stock holdings without any margins.

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