S&P warns: Banks' exposure to trading giants surges, U.S. financial ecosystem faces "endogenous fragility"

The deep entanglement between banks and trading giants is becoming a "time bomb" for the U.S. financial system.

S&P Global Ratings issued a report on Wednesday warning that U.S. banks’ total exposure to hedge funds and high-frequency trading firms has reached several trillion dollars, with tail risk remaining "elevated." Record leverage levels, a dramatic expansion in financing, and highly concentrated exposures among only a handful of large banks have collectively resulted in an ecosystem that "exhibits inherent fragility and may be tested under extreme stress scenarios."

Trading firms such as Jane Street and Citadel Securities have become a formidable force on Wall Street, and their rise is highly dependent on financing support from traditional investment banks. Meanwhile, market financing revenues at large investment banks have repeatedly hit record highs, with both sides deepening their mutual dependence. For investors, if the market were to experience violent volatility or a counterparty default, the impact on banks’ balance sheets could be far greater than anticipated.

Scale Doubled in Four Years, Risks Accumulating in Tandem

According to S&P data, prime brokerage lending volume in 2024—which includes market financing and other post-trade services provided to hedge funds—has exceeded $2.5 trillion, doubling compared to four years ago.

This business has become an important revenue pillar for large investment banks. S&P estimates that Goldman Sachs, Morgan Stanley, Barclays, and BNP Paribas will together generate $25 billion in revenues from market financing in 2025, an increase of 25% year-on-year, and this figure may still underestimate the actual total.

Data disclosed by Goldman Sachs this week shows that, of the $5.3 billion in equity trading revenue for the first quarter of this year, nearly half came from financing, with a year-on-year increase of nearly 60%; fixed income contributed another approximately $1 billion in financing revenue.

However, S&P points out that this type of short-term financing could evolve into long-term funding commitments, eroding bank capital and putting pressure on credit ratings. “Market financing absorbs liquidity in the short term, while long-term client relationships require stable funding sources, and the counterparty and market risks incurred by trading inventory occupy regulatory capital,” the report stated.

Leverage at Record Highs, Basis Trade Risks under Scrutiny

Regulators are increasingly wary of the widespread adoption of “basis trades” by hedge funds. This strategy profits from arbitraging the small price differences between Treasury cash and futures contracts. Given the narrow spreads, traders must use substantial leverage provided by banks to be profitable.

According to Federal Reserve data, hedge fund leverage at the start of last year had already reached an all-time high, supporting large positions in the Treasury, rates derivatives, and equities markets.

S&P’s report warns: “The rampant usage of this strategy intensifies second-order risks across the industry. If markets experience volatility or counterparties default, and leveraged positions are forced to be unwound quickly, banks’ prime brokerage and securities financing divisions will be exposed to significant risk.”

Lessons from History Linger, Risk Concerns Persist

History shows that when such risks materialize, consequences can be severe. The collapse of the family office Archegos Capital Management in 2021 resulted in over $10 billion in losses for its prime brokerages, with Credit Suisse hit particularly hard.

The S&P report emphasizes that banks’ total exposure to hedge funds and trading firms means tail risk is “relatively high”—the probability may be low, but the impact, should such events occur, would be very significant.

The scale of trading firms like Jane Street is already formidable. According to reports, Jane Street’s trading revenue in the second quarter last year exceeded $10 billion, surpassing JPMorgan and Goldman Sachs for the same period. As these institutions continue to grow their market share, their deep entanglement with the banking system has become a potential risk point that regulators and market participants must continue to scrutinize.