Kochi: The second weekly derivatives expiry under SEBI's newly introduced Closing Auction Session (CAS) again put India's equity derivatives market under the spotlight on Thursda.
The unusual movements in benchmark closing values renewed debate over settlement price discovery even as market volatility eased compared with the previous sessions.
While brokers and traders continued to flag distortions in expiry-day settlements under the new mechanism, the Securities and Exchange Board of India (SEBI) has ruled out any rollback, preferring instead to improve investor awareness and the display of indicative auction prices as market participants adjust to the new system.
Viewed in isolation, the latest episode appears to be about a new method of discovering closing prices.
Viewed in a broader context, however, it represents the latest milestone in what increasingly appears to be a gradual but significant and ongoing exercise to reshape India's equity derivatives market by SEBI and the Reserve Bank of India (RBI).
A pattern is emerging
Over the past year, regulators have introduced a succession of measures that, at first glance, appeared unrelated.
SEBI increased contract sizes to curb excessive retail speculation. Weekly expiries were rationalised.
The RBI tightened access to bank funding for proprietary trading firms. SEBI subsequently approved derivatives linked to the Nifty India FPI 150 Index to broaden institutional participation and proposed changes to the margin framework to encourage longer-tenure and defined-risk strategies.
The latest addition has been the introduction of the Closing Auction Session (CAS) and the extension of derivatives trading hours to align with the new settlement framework.
Each initiative addresses a specific issue. Collectively, however, they suggest a discernible shift in regulatory thinking.
Beyond trading volumes
For years, India's derivatives market was celebrated for its rapid expansion, eventually becoming the world's largest by contract volumes.
Regulatory success was often associated with rising turnover, growing participation and increasing liquidity.
The recent measures suggest that the emphasis is gradually moving beyond the quantity of trading towards the quality of participation.
"Instead of merely facilitating higher trading activity, regulators now appear increasingly focused on improving price discovery, strengthening settlement integrity, encouraging genuine hedging and reducing excessive speculative leverage without undermining market liquidity," said an analyst at a leading brokerage house in Mumbai.
That changing emphasis is reflected even in the latest Closing Auction Session.
Why the closing auction matters
Until last week, closing prices for most stocks were determined using the volume-weighted average price (VWAP) of trades executed during the final 30 minutes of trading.
Under the new framework, closing prices for F&O stocks are now determined through a dedicated auction process that seeks to establish a single equilibrium price after aggregating buy and sell orders.
The objective is to produce a closing price that is more representative, transparent and less susceptible to distortions, particularly because these prices serve as benchmarks for derivatives settlement and index calculations.
The transition, however, has not been seamless.
The first few sessions witnessed sharp divergences between the Nifty and Sensex near the close, creating uncertainty for traders, particularly on weekly expiry days.
Thursday's expiry again highlighted the market's adjustment process, although volatility eased compared with earlier sessions as participants became more familiar with the new mechanism.
Not an isolated reform
The Closing Auction Session is only the latest in a sequence of regulatory interventions.
Earlier this year, the RBI's tighter norms on bank lending for proprietary trading contributed to a noticeable decline in derivatives turnover as proprietary traders recalibrated their positions.
SEBI has simultaneously been working on redesigning the derivatives ecosystem by proposing a margin framework that rewards defined-risk and longer-tenure positions while discouraging excessive concentration in near-term speculative contracts.
The approval of derivatives linked to the Nifty India FPI 150 Index also signals an effort to broaden participation among overseas institutional investors rather than relying predominantly on high-frequency retail trading.
Taken together, these developments point to something more fundamental than a series of operational changes.
Changing market behaviour
The cumulative effect of these initiatives appears aimed at influencing not merely how much derivatives trading takes place, but the nature of that trading.
The regulatory emphasis increasingly appears to favour better risk transfer, improved market resilience and stronger price discovery over short-term speculative turnover.
That does not necessarily imply regulators are seeking lower trading volumes. Instead, the objective appears to be a market where liquidity is supported by genuine hedging and institutional participation rather than excessive leverage or speculative concentration.
A new phase
Whether the latest reforms ultimately strike the right balance between liquidity and market stability will become evident only over time.
For now, however, the direction of travel appears increasingly clear.
India's derivatives market is no longer evolving solely through market forces or isolated regulatory tweaks. Rather, it is being recalibrated through a series of interconnected reforms that, taken together, seek to redefine not just how the market functions, but what regulators expect it to achieve.
