Tensions are escalating between traditional Wall Street banks and non-bank trading firms, with JPMorgan taking a decisive step to curtail its financial backing of Jane Street.

According to sources familiar with the matter, JPMorgan significantly reduced the bond trading financing it provides to Jane Street last year. The catalyst for this move was Jane Street's expansion into US Treasury market-making, which directly competes with JPMorgan's own operations. This reduction signals a notable deterioration in the relationship between America's largest bank and one of its most significant non-bank clients.

The financing cut reportedly represents approximately 5% of Jane Street's total fixed-income financing across all banks and did not materially impact the firm's 2025 revenue. However, the message behind the action carries far more weight than the numbers suggest. It highlights a growing internal conflict at JPMorgan as the bank grapples with having funded a formidable competitor while simultaneously facing the erosion of its core business.

Jane Street's Bold Move into Bond Markets Reshapes Competition

Jane Street has evolved from a relatively low-profile proprietary trading firm into a major global market participant. Last year, the company executed over $900 billion in bond trading, and its full-year 2024 trading revenue reached $40 billion — a mere $1 billion behind JPMorgan's own figure.

Jane Street's entry into US Treasury market-making represents its latest direct challenge to traditional banking institutions. Raman Kalra, head of non-bank liquidity provider analysis at Crisil Coalition Greenwich, notes that as bond market trading shifts toward electronic platforms, trading firms such as Jane Street and Citadel Securities have reaped significant benefits. Fixed income was one of the few remaining markets where phone and voice trading still dominated. According to Crisil data, trading firms already account for 10% of total industry revenue across fixed income, currencies, and commodities in 2025.

Internal Friction Surfaces as Banks Question Their Role as Financiers

JPMorgan's financial support for Jane Street has sparked clear internal discontent. Sources reveal that the bank's traders are frustrated with having helped cultivate a powerful rival through the provision of financing — particularly within the fixed-income space.

Proprietary trading firms operate on their own capital but typically employ leverage to amplify returns, making bank financing a mutually beneficial and stable revenue stream for years. Yet, as the boundaries of non-bank institutions continue to expand, this delicate balance is being disrupted.

JPMorgan's change in stance is not an isolated move. The bank also reduced certain trading services for Citadel Securities after the firm launched client-facing offerings that compete directly with JPMorgan's equities business. In his annual shareholder letter released in April, JPMorgan CEO Jamie Dimon explicitly listed Citadel Securities as an emerging competitor.

Jane Street's Rapid Expansion Carries Growing Risks

Despite its impressive revenue figures, Jane Street's aggressive strategy is beginning to show signs of strain. The firm has recorded losses on some of its positions this year — with reports indicating approximately $15 billion in losses during July alone, linked to AI-related trading positions and its investment in Situational Awareness, the hedge fund run by 24-year-old Leopold Aschenbrenner.

Jane Street's rapid growth has been partly driven by its willingness to take on risk exposures that banks have generally avoided since the 2008 financial crisis. While this approach has delivered substantial returns during favorable market conditions, it also exposes the firm to greater downside pressure during periods of heightened market volatility.