The rivalry between India’s two stock exchanges is set to intensify, with the National Stock Exchange (NSE) shifting the expiry day for its weekly Nifty options contract to Monday from Thursday, starting 4 April. The move comes just a day before the weekly expiry of BSE’s Sensex options, potentially cutting into BSE’s trading volumes, which tend to peak on Mondays and Tuesdays.
A circular from NSE, issued after market hours on Tuesday, triggered a 5% fall in BSE shares to ₹4,230 at the time of writing, even as benchmark indices Nifty and Sensex gained over 1% intraday.
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“The change of expiry day will hot up the competition between the rival bourses,” said Rajesh Palviya , senior vice president, derivatives and technical research, at Axis Securities.
“Sensex weekly volumes spike on Monday and Tuesday as traders wanting to play close to expiry build up volumes on those days,” said a broking official, requesting anonymity. “This move will impact the BSE Sensex weekly volumes on the two days.”
The change affects all index and stock derivatives contracts. The last expiry day under the current schedule is 3 April, a Thursday.
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NSE’s move comes as BSE has been gaining ground in the derivatives market, helped by Securities Exchange Board of India (Sebi) directives aimed at creating a level playing field and reducing concentration risk on a single exchange.
While BSE lags NSE by a wide margin, its Sensex weekly options have gained traction in recent years. For instance, BSE’s market share, based on average daily derivatives turnover on a notional basis, climbed from less than 1% in FY23 to 26% this fiscal, with NSE commanding the remainder.
In October, in response to retail traders’ heavy losses— ₹1.8 trillion over FY22-24—Sebi mandated that each national exchange could list only one weekly index options contract, down from four for NSE and two for BSE.
This forced NSE to discontinue its hugely popular Bank Nifty weekly options, which had accounted for about 55% of its index options turnover, leaving only Nifty weekly options.
The regulatory move boosted BSE’s Sensex options volumes, driving BSE shares up 66% from ₹3,685 at the end of September to a record ₹6,133.4 on 20 January even as the Nifty fell nearly 10% to 23,345 in the same period.
Weekly index options remain the most traded instrument among both retail and institutional investors.
BSE had already adjusted its own index derivatives expiry to Tuesday from Friday, effective 1 January, in an effort to capture market share.
