BSE Share Price: Asia’s Oldest Stock Exchange Slumps 4%, Extends Weekly Losses To 10%—Here’s Why

The Indian stock market bourse BSE Sensex's share price fell 4 per cent on Friday, July 11, continuing its downtrend in the past one week to 10 per cent after reports circulated of Sebi's extended investigation into dupious practices by Jane Street.

Meanwhile, BSE share price is down 16 per cent since last Thursday, the same day the Securities and Exchange of India (Sebi) interim order declared a ban on the US trading firm.

Market regulator Sebi extends probe on Jane Street Group

Earlier, the investigation was limited to the National Stock Exchange (NSE) and now reportedly it involves Bombay Stock Exchange (BSE), as sensex contracts have gained in the past financial years.

Sebi has banned Jane Street from accessing the Indian stock market for manipulating indices like the Nifty 50 and Nifty Bank on expiry days.

The market regulator also directed the trading firm to deposit alleged illegal gains of Rs 4,843.5 crore, which Sebi said were made unlawfully.

Also Read: Silver Hits Historic Rs 1.11 Lakh Per Kg in India: What's Driving This?

From January 2023 to March 2025, Jane Street's total profit from trading index stocks and derivatives, and the cash market was Rs 36,502.12 crore.

While Nifty 50 and Bank Nifty contracts are highly popular, the Sensex is the third most popular options index. However, the trading volumes on BSE are a miniscule of that of the NSE. NSE has a nearly 95 per cent market share in India's F&O market. Meanwhile, India accounts for roughly 60 per cent of global equity derivative trading volume, according to the Futures Industry Association.

Sebi's Ban On Jane Street

On July 4, Sebi banned Jane Street which has squeezed volumes in the country's options market, according to a Reuters report.

Since the order, index options premium turnover on the NSE and BSE exchanges declined on a week-on-week basis in four of five sessions.

This metric, representing the total value of premiums paid to buy index options like the Nifty 50, serves as a key indicator of real capital at play, risk appetite, and overall sentiment in the derivatives market.