The Securities and Exchange Board of India (SEBI) is set to review the methodology for determining settlement prices of derivative contracts on expiry. This initiative comes as a response to significant market fluctuations, including a notable 2,000-point drop in the Sensex during a recent Closing Auction Session (CAS), which raised concerns among market participants.
Context of the Review
SEBI’s decision to review the CAS mechanism stems from feedback gathered from various stakeholders in the market, including traders and institutional investors. The CAS was introduced to determine closing prices of equities and consequently set the basis for settlement prices of derivatives. Since its implementation on August 3, 2026, the CAS had been monitored closely by SEBI to assess its impact on market dynamics.
The feedback has highlighted discrepancies resulting from abrupt price movements, as evidenced by the dramatic decline observed in the Sensex. During the last CAS session, the index plunged sharply, prompting a spike in put option prices and raising questions on the robustness of the current settlement system.
SEBI’s Consultation Process
SEBI plans to issue a consultation paper within a week, detailing proposed changes to the current derivatives settlement price methodology. This paper will seek insights and opinions from diverse market participants, including brokers, stock exchanges, and mutual funds, ensuring that the perspectives of all involved are considered.
The CAS’s incorporation into the derivatives settlement framework was originally based on extensive deliberations, involving two rounds of public consultations in December 2024 and August 2025. SEBI aims to engage with stakeholders again to refine the settlement processes based on the challenges noted during the CAS’s initial implementation period.
The Role of Volume Weighted Average Price (VWAP)
In conjunction with the CAS review, exchanges will now utilize the Volume Weighted Average Price (VWAP) during specific trading hours—3:00 PM to 3:15 PM—to determine reference prices for stock and index futures. This method is intended to mitigate the volatility witnessed during the CAS, providing a more stable basis for settlement in the face of rapid market changes.
This move aligns with global best practices aimed at providing a fair pricing mechanism in volatile market scenarios, ensuring that settlement prices reflect actual market conditions more accurately.
What This Means
The review of the settlement methodology by SEBI is significant for multiple reasons. Firstly, it acknowledges the volatility currently observed in the Indian equity markets and aims to establish mechanisms that can adapt to sudden price swings. By contemplating adjustments based on stakeholder feedback, SEBI looks to enhance the integrity and stability of derivative transactions. Furthermore, the adoption of VWAP is a step toward modernizing trading practices, which could lead to increased investor confidence in the Indian market.
For investors, the potential reforms may eventually translate into more predictable trading conditions, though they will need to stay updated with SEBI’s forthcoming consultation paper to understand the practical implications of any changes proposed.
Frequently Asked Questions
What is the Closing Auction Session (CAS)?
The CAS is a mechanism introduced by SEBI to determine the closing prices of securities in the equity cash segment, which in turn influences the settlement prices for derivative contracts during expiry.
Why did the Sensex drop 2,000 points during the CAS?
The substantial decline occurred due to market fluctuations influenced by various factors, contributing to heightened volatility during the closing auction session.
What changes can we expect in the derivative settlement price methodology?
SEBI is expected to propose changes aimed at improving the existing framework based on stakeholder feedback collected during the review period, with specific details to be outlined in an upcoming consultation paper.
How will VWAP affect trading in Indian markets?
The introduction of VWAP for determining reference prices during specific trading hours is expected to stabilize price fluctuations during the CAS, leading to a more accurate reflection of market conditions in settlement prices.







