SEBI announced a revised trading framework that will take effect on Monday, 3 August. The changes are designed to make price discovery more accurate and to bring India’s markets in line with global best practices.
A key feature is the new Closing Auction Session (CAS) for F&O‑eligible Category I stocks. The CAS is meant to improve market efficiency by determining a fair closing price through an auction process.
During the regular trading day, the equity cash market will continue to run until 3:15 pm. After that, a transition period from 3:15 pm to 3:20 pm will prepare the market for the auction.
The first part of the auction, CAS Order Entry I, runs from 3:20 pm to 3:25 pm. The second part, CAS Order Entry II, follows from 3:25 pm to 3:30 pm. In this second phase, investors cannot modify or cancel orders, and the auction will end randomly within the final two minutes.
Order matching takes place between 3:30 pm and 3:35 pm. The price discovered during this period becomes the official closing price for all F&O‑eligible stocks.
Stocks that are not eligible for F&O trading remain unchanged; they still close at 3:30 pm. The equity derivatives market, however, now has an extra ten minutes and will close at 3:40 pm.
SEBI also revised the pre‑open session. Order entry for the pre‑open window is now from 9:00 am to 9:07 am. Order matching follows from 9:07 am to 9:15 am, after which regular trading begins at 9:15 am.
According to SEBI, the Closing Auction Session will provide a transparent closing price, improve execution efficiency by pooling liquidity, give all investors equal access, reduce tracking errors for passive funds, and align India’s market structure with global standards.
Investors will need to adjust their trading strategies to accommodate the new timings. Keeping track of the revised schedule will help traders and fund managers avoid confusion and make the most of the extended trading hours and the new auction mechanism.