SEBI has barred US-based Jane Street Group from participating in the Indian stock market and ordered it to disgorge unlawful gains of ₹4,843 crore for allegedly manipulating stock indices through derivative positions.

Large buy or sell orders—executed seconds before close—nudge prices just enough to swing the outcome of options and futures contracts. It’s subtle. It’s fast.

The lawsuit alleged that the traders had stolen a “ highly valuable, unique, and proprietary ” trading strategy, which was quickly revealed to revolve around India’s booming options market. Jane Street and Millennium settled the lawsuit in December, but judging from SEBI’s report it has cast a long (and expensive) shadow.