Shares of BSE Ltd. plunged over 6% to an intraday low of Rs. 2,500 on June 18, following a regulatory move by the Securities and Exchange Board of India (SEBI) that is set to reshape competition in India’s derivatives market. SEBI has approved the National Stock Exchange's (NSE) proposal to move its weekly equity derivatives expiry day from Thursday to Tuesday, effective September 1, 2025.