New CAS Framework Enhances Transparency and Detects Market Abuse, SEBI Announces

SEBI’s latest Closing Auction Session (CAS) system is set to improve the fairness of price discovery for Indian equities, the regulator announced on August 19. Chairman Tuhin Kanti Pandey said the upgraded mechanism offers a higher detection rate for potential market manipulation compared with the legacy volume‑weighted average price (VWAP) approach.

The CAS operates as a distinct 20‑minute auction where all buy and sell orders are pooled. The closing price is then fixed at the level where the greatest volume of shares can be traded, ensuring a more representative market price.

Pandey stressed that the new framework not only boosts transparency but also strengthens execution capacity for large orders, addressing concerns that the previous method could be vulnerable to price distortion.

He concluded by urging participants to respect the integrity of the system, noting that any effort to undermine CAS will be swiftly penalised.