BSE shares rise by as much as around 5% on September 4 after SEBI says it is reviewing how derivatives settlement prices are determined following concerns linked to the Closing Auction Session (CAS). Reports cite SEBI’s statement after the regulator considered feedback from market participants, with BSE shares trading higher in morning trade.

CAS was introduced in the equity cash segment on August 3 to determine official stock closing prices. Under the framework, the CAS-derived closing price is used to settle derivatives contracts on expiry days. Several outlets note that market participants flagged issues such as differences in index closing levels across exchanges, sharp swings in options prices around expiry, and potential concerns over liquidity during the closing auction. BSE executives also point to limited participation in the auction session and suggest possible changes, including separating futures and options expiry from the CAS process.

Outlets differ mainly in emphasis: some focus on the stock price reaction and specific trading moves in BSE shares and options, while others concentrate on SEBI’s process for amendments. Economic Times and NDTV report that SEBI plans to issue a discussion or consultation paper within about a week for further input, while Free Press Journal adds details of stakeholder concerns and BSE’s internal feedback collection.