India has barred one of the world's largest quant trading firms, Jane Street, from accessing its securities market after an investigation found it made "unlawful gains", taking the most stringent action ever against a foreign trading firm.

India has barred Jane Street from the country’s financial markets and said it would seize around $570 million that the U.S. securities firm made from allegedly fraudulent trades.

The Securities and Exchange Board of India allege that the US trading firm made $550mn of illegal gains from these strategies, which it is now wants back before the ban will be lifted. As MainFT reported: The Securities and Exchange Board of India said its decision to limit Jane Street’s access to India’s securities markets stemmed from a months-long investigation.