More than a year ago, on options expiry days, which are trading sessions when bets are settled, Mayank Bansal began to notice something odd. Prices were moving just before the close in ways that felt too precise. Someone was winning too perfectly.

Mayank, a United Arab Emirates (UAE)-based hedge fund manager, had spent years studying options — cheap, high-risk contracts that let you bet on where markets will go. If you're right, the profits can be huge. If you're wrong, which is what most retail investors are, you lose everything.

A U.S. court case would later point to Jane Street — one of the world’s most powerful proprietary trading firms, which means it trades using its own money, not clients’. Known for its lightning-fast algorithms and puzzle-solving traders, Jane Street had made over $4 billion in India in just two years.

India’s market regulator the Securities and Exchange Board of India (SEBI) says Jane Street placed large trades in a few key stocks just before the market closed. These trades pushed the index in just the right direction to make their options bets pay off, a tactic that SEBI calls a “well-planned and sinister” scheme. Jane Street denies any wrongdoing.

In this episode, Mayank tells us what he saw and why it raises serious questions about who really wins in India’s booming options market.

Guest: Mayank Bansal, a United Arab Emirates (UAE)-based hedge fund manager

Host: Anupama Chandrasekaran

Produced by Jude Francis Weston

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