Jane Street Capital has become a leading player in Asia’s multibillion-dollar block trading market, stepping into a role previously held by hedge funds following the closure of Segantii, the firm led by Simon Sadler. According to industry sources, the New York-based proprietary trading firm is now considered among the top three such buyers by investment bank equity syndicate and trading desks seeking purchasers for large parcels of shares in Asian companies.

Block trading involves the acquisition or sale of significant quantities of shares, typically at a discount to prevailing market prices. It allows sellers to divest large holdings in a single transaction, avoiding the market impact that would occur if they sold gradually on public exchanges. However, this segment of equity capital markets remains largely opaque, with block transactions rarely disclosed publicly and communications between banks and prospective buyers subject to increasing regulatory scrutiny, notably in Hong Kong.

Data from Dealogic indicates that total block sales across Asia exceeded $48 billion in 2024 and 2025, with Indian-listed companies registering the highest volumes, followed by those in Hong Kong and Japan.

Jane Street’s rise in Asia coincides with the exit of Segantii, which had been a dominant force in the region’s block trading scene. Segantii closed in 2024 after Sadler, also known as the chair of Blackpool Football Club, was charged by Hong Kong regulators with insider trading related to transactions involving the clothing retailer Esprit. Sadler’s trial in Hong Kong began in May, during which he has pleaded not guilty.

Prior to its elevation to a leading position, Jane Street was active but not among the top-tier block traders in Asia, industry insiders noted. The firm’s growth and ability to manage market risk effectively have contributed to its improved standing. Sources highlighted Jane Street’s capacity to hold positions for longer periods than many hedge funds, thanks in part to its increasing scale and a large balance sheet. This approach reportedly makes it a more attractive partner for block trading activities.

Despite these gains, Jane Street has faced challenges. In July, the firm recorded its first monthly loss in a decade amid a broad sell-off in AI-related stocks. Yet, market participants remarked that block trading remains a niche where firms can generate excess returns through relationships with syndicate desks.

Jane Street has demonstrated a strong commitment to its Asian operations, establishing its regional headquarters in Hong Kong last year by leasing six floors of a new harborside office complex at a reported cost of about $4 million per month.

The firm declined to comment on its recent developments in the Asian block trading market.