MUMBAI, Nov. 10 -- The closing auction session (CAS) has contributed to a widening earnings divide between India's equity and commodity exchanges, weighing on profits at the former while the latter has continued to grow. In the July-September quarter, the National Stock Exchange (NSE) and BSE reported sequential declines in profit as trading activity came under pressure. The Multi Commodity Exchange (MCX), by contrast, benefited from heightened activity in gold and silver, extending its earnings growth. The outlook for the three exchanges could shift. With the Securities and Exchange Board of India (Sebi) rolling back CAS and restoring the earlier settlement mechanism, trading volumes could recover at equity exchanges, lifting profitability. For MCX, the key question is whether volatility in gold and silver prices can sustain the levels that have driven its recent growth. NSE's net profit fell 17% sequentially to Rs.2,578 crore in the second quarter of fiscal year 2027 (Q2FY27), according to its investor presentation. Its revenue from operations declined 11% quarter-on-quarter (QoQ) to Rs.4,067 crore. BSE reported a 7.4% sequential fall in net profit to Rs.807 crore, while its revenue from operations fell 8.5% to Rs.1,432 crore. MCX, meanwhile, posted a 10.1% sequential rise in net profit to Rs.455 crore, while revenue grew 14% QoQ. The fall in trading activity at the exchanges is reflected in derivatives turnover. NSE's average daily notional turnover in equity options fell 16% sequentially in Q2, while BSE's average daily notional turnover in derivatives fell 25%. "With the removal of CAS, we have seen trading volume revive in the October-month series, and is expected to be back to levels before CAS," said Shrikant Chouhan, head of equity research at Kotak Neo. The recovery in sentiment is also reflected in the share prices. NSE shares have risen 8.8% since 15 October, when Sebi rolled back CAS, while BSE shares have gained 10.8%. Sebi restored the 30-minute volume-weighted average price (VWAP) for settling derivatives contracts on expiry days. The changes will take effect on 7 December. The move followed concerns that the framework, introduced on 3 August, had triggered abrupt price swings and uncertainty over settlement values on expiry days, prompting market participants to flag risks to liquidity and price discovery....