量化巨头，突遭封杀！

Core Viewpoint - Jane Street, a prominent quantitative trading firm, faces significant penalties in India for market manipulation, including a temporary market ban and the forfeiture of illegal gains amounting to 48.4 billion Indian Rupees (approximately 4 billion RMB) [1][4][19]. Group 1: Regulatory Actions - The Securities and Exchange Board of India (SEBI) issued a temporary ban on Jane Street, citing "malicious manipulation schemes" and requiring the firm to return 48.4 billion Indian Rupees (approximately 4 billion RMB) in illegal profits [4][8]. - SEBI's 105-page temporary order detailed the firm's manipulative practices, confirming rumors of substantial profits made by Jane Street in the Indian market [6][19]. - Jane Street is required to close or settle any open positions within three months of the order or upon the expiration of relevant contracts, whichever comes first [5]. Group 2: Financial Gains and Market Impact - From January 2023 to March 2025, Jane Street reportedly made profits of approximately 365 billion Indian Rupees (around 30.6 billion RMB) in India's derivatives and spot markets [2][7]. - On January 17, 2024, Jane Street achieved a single-day profit of 86 million USD, marking its most profitable day in the Indian market [13]. - The firm accounted for approximately 15% to 25% of the total market trading value on that day, with a net trading value of about 5.11 billion USD, significantly surpassing its competitors [14]. Group 3: Manipulative Strategies - Jane Street's manipulation involved a three-phase strategy: building positions by aggressively buying BANKNIFTY index components, arbitraging by selling call options and buying put options, and finally profiting by systematically closing positions as stock prices fell [16][17][18]. - The firm was accused of using substantial funds to influence the prices of low-volume futures and spot markets, misleading retail investors into unfavorable trades [9][19]. - SEBI's investigation was triggered by a lawsuit filed by Jane Street against former employees, which revealed details of the firm's proprietary trading strategies focused on India's growing options market [9][10]. Group 4: Market Context - The Indian derivatives market has seen a surge in retail investor participation, becoming the largest in global contract trading volume, with the options premium size increasing elevenfold over five years [20]. - Foreign funds and domestic proprietary firms reportedly made a gross profit of 7 billion USD in the 12 months leading up to March 2024, while retail investors suffered losses of up to 21 billion USD in futures and options trading during the same period [21].