SEBI Moves to Overhaul Derivatives Settlement After CAS Volatility
SEBI has initiated a review of its derivatives settlement price methodology following abnormal closing-auction-session (CAS) volatility that distorted F&O expiry pricing in August 2026. Economic Times Markets reported that the proposed change — shifting from CAS-based to volume-weighted average pricing — would directly affect how Nifty and Bank Nifty option settlements are calculated on expiry day. For F&O traders, this is structural: settlement-week gamma strategies, particularly short-strangle setups that rely on predictable expiry-day price anchoring, would need to be recalibrated from October onwards. Mint Markets also confirmed SEBI is soliciting industry comment before the rule takes effect, suggesting an October or November implementation timeline.
Read at Economic Times Markets ↗