The National Stock Exchange (NSE) has tightened the list of securities eligible as collateral for margin funding, removing 1,010 stocks, including Adani Power, YES Bank, and Paytm, from the previous list of 1,730. The new criteria require securities to have been traded at least 99% of days in the last six months and have an impact cost of up to 0.1% for an order value of Rs 1 lakh.