Ananth Narayan, a senior figure at the Securities and Exchange Board of India (SEBI), has become the central figure in one of the most significant crackdowns in Indian financial regulatory history. As a former derivatives trader who transitioned into a regulatory role, Narayan spearheaded the investigation into alleged market manipulation by Jane Street, a U.S.-based proprietary trading firm, within India's financial markets.

In July 2025, Narayan signed SEBI's interim order that barred Jane Street from Indian markets and froze ₹4,843 crore (approximately $570 million) in alleged illegal gains. The report accused the firm of manipulating the prices of the Bank Nifty and Nifty indices through coordinated expiry-day trades and aggressive high-frequency strategies, which purportedly caused substantial harm to small Indian investors. Narayan didn't hold back in his assessment, stating that "The JS Group is not a good faith actor… The faith of millions of small investors and traders can no longer be held hostage to the machinations of such an untrustworthy actor". This strong indictment reverberated globally, signaling a turning point in the scrutiny of foreign firms operating within India's financial system.

Narayan's unique background sets him apart. Before joining SEBI in 2022, he held senior positions at Deutsche Bank, Citigroup, and Standard Chartered, accumulating extensive experience in currencies, rates, and derivatives. He is the only SEBI board member with such in-depth trading experience, which has uniquely positioned him to understand the complexities of Jane Street's strategies. According to colleagues, his trading acumen was crucial to deciphering the firm's tactics. He has also been consulted by the Reserve Bank of India (RBI) when the central bank sought insights into current market dynamics.

The investigation led by Narayan involved multiple departments and uncovered patterns suggesting that Jane Street systematically profited at the expense of retail investors. SEBI alleged that Jane Street made around Rs 36,500 crore in unlawful profits through calculated trading strategies across multiple segments, including cash equities, stock futures, index futures, and index options. The regulatory investigation revealed that Jane Street maintained "consistently the largest risks in 'cash equivalent' terms in F&O, particularly on index option expiry days". The order particularly focused on January 17, 2024, Jane Street's most profitable day in two years, accusing the firm of timing its trades to manipulate the Nifty Bank Index before offloading bearish bets.

Narayan's journey began in Kolkata, followed by an engineering degree from IIT Bombay and an MBA from IIM Lucknow. He spent two decades in trading before transitioning to academia and regulation. Known for his precision and risk management skills, Narayan reportedly keeps a sign in his office that reads: "First, do no harm".

SEBI has conditionally lifted the trading ban on Jane Street after the firm deposited ₹4,844 crore in an escrow account. Stock exchanges are directed to closely monitor Jane Street's dealings to prevent manipulative activities during the ongoing investigation. While SEBI monitors closely, Jane Street has committed to refrain from options trading and cash transactions until clarifying past trades. Jane Street maintains that SEBI's order reflects a misunderstanding of standard hedging practices. Jane Street has sought an extension to respond to SEBI's accusations of index manipulation and has requested data from the regulator to be able to respond to the order.

Narayan's actions reflect a broader shift in how India is policing its rapidly growing financial markets. He had observed firsthand how retail investors were losing significant amounts in derivatives trading. For Narayan, the issue extends beyond Jane Street; it's about maintaining the integrity of the market. He believes the real harm lies in allowing unchecked complexity to go unchallenged. In a sector where firms rarely face such scrutiny, Narayan has taken a bold step by challenging Jane Street's actions.