Both the exchanges will keep the expiry day of derivatives contracts unchanged for the existing contracts except for long dated index options contracts.
NSE is shifting the expiry day for index and stock derivatives from Thursday to Tuesday. Its monthly contracts will expire on the last Tuesday of every month starting September 1. Contracts expiring on or before August 31, will continue with Thursday expiry.

BSE will move its derivatives expiry from Tuesday to Thursday. The exchange’s monthly contracts will expire on the last Thursday of each month from September 1. Contracts expiring on or before August 31, will continue to expire on Tuesday. “It’s a win-win for both exchanges,” said Chandan Taparia, head of technical and derivatives research at Motilal Oswal Financial Services. “Going ahead we see that short-term traders may prefer NSE, while positional traders can benefit from BSE.” The decision of both the bourses to move to the new derivative expiry days came after Sebi mandated that expiries of all equity derivatives contracts will be limited to two days a week – either Tuesdays or Thursdays.