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.

US-based trading firm Jane Street has been banned from Indian markets after SEBI uncovered an alleged ‘intra-day index manipulation’ strategy that helped the firm earn ₹735 crore in a single trading day—raising serious concerns about algorithmic trading in

India’s regulator has temporarily barred Jane Street from accessing the local securities market, dealing a severe hit to the US firm that allegedly made $4.3 billion in trading gains in the South Asian nation in more than two years.