Mumbai, May 6 -- A Mumbai-based stock exchange's revival efforts have hit a roadblock after markets regulator, Securities and Exchange Board of India (Sebi), proposed to cap index derivative expiries to two days a week. In December 2024, the Metropolitan Stock Exchange of India (MSEI) raised Rs.238 crore from broking firm Groww's parent Billionbrains Garage Ventures, Zerodha's Rainmatter Investments, Share India Securities, and Securocorp Securities India. The bourse planned to offer a derivative contract for its flagship SX40 index. All National Stock Exchange Ltd's derivatives expire on Thursday, BSE Ltd's on Tuesday, and the MSEI had set Friday expiry for its SX40 contracts. The exchange offers trading but generates modest daily volumes ...