Closing Auction Session (CAS): How NSE and BSE Determine Stock Closing Prices
The Closing Auction Session (CAS) is a new mechanism introduced in India’s stock market to determine the official closing price of eligible stocks. The system is now used by both the National Stock Exchange (NSE) and BSE CAS became effective from August 3, 2026, initially covering stocks in the cash market that have derivatives contracts available. It replaced the earlier closing-price