Nithin Kamath Warns of Challenges Ahead as NSE and BSE Revamp Trading Procedures

India's financial landscape is poised for a major transformation starting August 3, as the National Stock Exchange (NSE) and the Bombay Stock Exchange (BSE) introduce a new operational framework known as the Closing Auction Session (CAS) for stocks that have futures and options (F&O) contracts. This innovative approach aims to enhance the accuracy and fairness of closing prices, yet Nithin Kamath, the co-founder and CEO of Zerodha, has expressed concerns that this shift could complicate the trading experience for both investors and brokerage firms. In a recent post on X, Kamath highlighted that while the new structure is expected to have a limited financial impact on brokerage operations, including Zerodha, there may be an initial struggle for investors to adapt to the revised trading schedule, leading to a surge in customer support inquiries. He candidly noted, "Now that broking is listed and people are looking more closely at the business, the honest bit: this will probably knock off some revenue, perhaps around 1–5 percent of brokerage income."

The Closing Auction Session (CAS) represents a significant shift in how closing prices are determined. Instead of relying on continuous trading to establish these prices, the CAS will create a dedicated auction window after regular trading hours for stocks with F&O contracts. During this period, all buy and sell orders will be aggregated and matched at a single equilibrium price. Kamath pointed out that this auction mechanism is not a novel concept in the global context, as several major stock exchanges, including the New York Stock Exchange (NYSE) and the London Stock Exchange (LSE), have already implemented similar systems to determine their closing prices. Currently, the closing price of stocks in India is calculated based on the volume-weighted average price (VWAP) of trades conducted in the last half hour of trading. Under the new CAS framework, however, orders will be collected and executed collectively at a price established through the auction process.