New Delhi, July 4 -- The Securities and Exchange Board of India (SEBI) has barred four entities of the Jane Street Group from accessing Indian securities markets, alleging fraud and manipulation in the derivatives segment.

In its 105-page interim order, SEBI revealed a sophisticated, expiry-day-centric trading strategy deployed by the US-based proprietary trading firm. The order details how the Jane Street Group manipulated index levels through aggressive buying and selling of key Bank Nifty and Nifty 50 constituent stocks, thereby influencing options pricing to generate substantial profits.

SEBI identified 18 trading sessions - 15 involving Bank Nifty and three involving Nifty 50 - where the group allegedly engaged in "sharp, large, an...