Goldman Sachs Expects BSE Sensex Expiry To Be Shifted To Thursday, Here's Why

Goldman Sachs anticipates a potential shift in the expiry day for BSE's Sensex index options, from the current Tuesday to Thursday.

This expectation, outlined in a recent research note, hinges on an ongoing regulatory review by the Securities and Exchange Board of India concerning equity derivative expiry days.

On March 27, SEBI released a consultation paper which proposed limiting expiry days for equity derivatives to either Tuesdays or Thursdays. On Thursday, NDTV Profit reported that the National Stock Exchange has likely applied for Tuesdays as its preferred expiry day for index derivatives.

"Based on the consultation paper as well as comments by the SEBI, if SEBI grants Tuesdays as expiry days for NSE index derivatives, we expect Thursdays will be the expiry days for BSE index derivatives," the Goldman Sachs note stated. Currently, BSE index options expire on Tuesdays, while NSE index options expire on Thursdays.

In January 2025, BSE had moved its index options expiry to Tuesday, with NSE concurrently on Thursday. This change, which followed the new regulation on rationalisation of index options, limited each exchange to one index contract expiry per week.

Consequently, BSE's share in index options had seen a notable increase based on premium turnover, rising from 16% in December 2024 to 23.6% in April 2025.

Goldman Sachs projects that if SEBI allows NSE to shift its expiry to Tuesday, it could impact BSE's market share.

While both exchanges could have the expiry for their index options contracts on the same day of the week, the brokerage expects Thursdays to be the expiry day for BSE index derivatives.

"The switch in expiry days, if approved by regulators, could reduce BSE’s market share in index options premium by 3-4 percentage points (or -15%) to approximately 18.8% from 22.2% so far this year," the note elaborated.

This analysis is based on year-to-date trading trends, which show Tuesdays as a particularly active day for options trading, accounting for 24% of India's options premium – higher than other weekdays (16-19%).

BSE currently commands a 40% market share on its Tuesday expiry.

SEBI is reportedly expected to announce its conclusions on the consultation paper later this month, May 2025.