The National Stock Exchange’s (NSE’s) plan to extend trading hours across the equity and, probably, the equity derivatives segments will have pros and cons. On the one hand, there is a strong case for keeping the markets open as long as possible. On the other hand, extended trading hours would have higher compliance costs. The NSE has permission to run the equity-based derivatives segment from 9 am to 11.55 pm (although in practice the session is open from 9.15 am to 3.30 pm, with trade modifications allowed until 4.15 pm) and to keep the equity cash segment open from 9 am to 5 pm, though this segment is normally open from 9.15 am till 3.30 pm, with order entries from 9 am onwards. The commodities derivatives exchanges are open from 9 am to 11.55 pm, while the currency markets are open from 9 am to 5 pm. Trading time in interest-rate derivatives has been extended till 5 pm.