Mumbai: The Securities and Exchange Board of India (SEBI) will roll out tighter rules on derivatives trading from October 1, including stricter position limits, enhanced monitoring and revised norms for stocks under the ban period.

The measures are designed to curb excessive speculation and better align risk with activity in the cash market, the regulator said.

Under the new framework, the market-wide position limit (MWPL), or the maximum number of bets permitted, will be tied to cash market volume and free float. It will be set at the lower of 15 per cent of free float or 65 times the cash volume across exchanges. MWPL will be updated quarterly based on rolling delivery volume data, a move SEBI said would also help reduce the risk of manipulation.

On stocks entering the ban period, futures equivalent open interest must be reduced by the next trading day, SEBI clarified. If open interest in a scrip exceeds 95 per cent of MWPL, traders will only be allowed to cut positions through offsetting trades.

From November 3, 2025, clearing corporations will also carry out random intraday checks, at least four times daily, on MWPL utilisation for single stocks. Exchanges may impose additional surveillance margins if breaches occur.

In another move, SEBI said that from December 6, 2025, pre-open sessions will be extended to the F&O segment to improve trading convenience and liquidity management, in line with cash market practices.

IANS