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.

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.

In a dramatic move that’s rattled India’s financial markets, the Securities and Exchange Board of India (SEBI) has banned the global trading giant Jane Street Group from participating in the country’s securities markets. The regulator accused the firm of orchestrating what it calls one of the boldest market manipulation schemes in Indian history.