As US stocks hover near historic highs, with technology and AI-related shares continuing to attract fervent demand, the US stock financing market is facing mounting strain.

Data from Morgan Stanley shows that on June 26th, the financing cost for stock positions briefly surged to a level approximately 200 basis points above the federal funds rate, marking the highest point since December 2024.

While a quarterly-settled measure has since retreated to 89 basis points, market participants warn that the structural factors pushing rates higher are not dissipating but are instead continuing to accumulate.

"The risk of a funding surge is likely to be with us for the foreseeable future," stated Morgan Stanley US interest rate strategist Martin Tobias.

This pressure, driven by leverage, is becoming the most easily overlooked hidden risk beneath the market's elevated levels.

Unusual Spike in Financing Costs: Leverage Demand Far Exceeds Norms

The stock repurchase (repo) market is at the center of this storm, where investors and traders borrow short-term cash using their held shares as collateral.

Typically, due to the high-quality collateral, stock financing rates are only a few basis points above benchmarks like the federal funds rate or the Secured Overnight Financing Rate (SOFR).

The situation at the end of June was markedly different, with costs rising sharply ahead of the quarter-end.

The anomaly stems from a severe mismatch between supply and demand.

Barclays US rates strategist Sam Earl attributes the recent pressure to a simple supply-demand issue—a surge in equity financing demand that dealer balance sheet capacity has failed to match.

He estimates the equity financing market is around $10 trillion, and a 10% increase in leveraged equity exposure translates to roughly $1 trillion in additional financing needs.

Coupled with robust growth from overseas markets, particularly in Asia, this demand is rapidly depleting available financing capacity.

Meanwhile, primary dealers' equity financing exposure remains near historic highs.

Even after the quarter-end effect faded, financing costs stayed elevated, a dynamic coinciding with record-high dealer exposure and borrowing activity heavily concentrated in a narrow group of stocks like technology and semiconductor companies.

Federal Reserve data shows dealers held approximately $211 billion of such exposure on their balance sheets as of June 24th.

Calculations by Morgan Stanley's Martin Tobias further indicate that the ratio of dealer equity repo exposure to the S&P 500's free-float market capitalization has climbed 50% over the past year, meaning each dollar of investable stock capital is increasingly reliant on leverage.

Structural Expansion of Leverage: From Margin Debt to Leveraged ETFs

Behind the soaring financing costs lies a systemic expansion of leverage in US stocks.

Margin debt has reached a record high.

According to the Financial Industry Regulatory Authority (FINRA), US margin debt hit a record $1.42 trillion in May 2026, up 8.5% month-over-month and 53.7% year-over-year.

Concurrently, US investors' net credit balance has plunged to a historic low of negative $991.7 billion, measuring the difference between cash and borrowed funds in margin accounts.

This trend is fueled by explosive growth in US leveraged ETFs.

Bloomberg data shows the total assets of US leveraged and inverse-leveraged equity ETFs are nearing $200 billion, with a staggering 85% concentrated in technology, AI, and semiconductor sectors.

The Direxion Daily Semiconductor Bull 3X Shares ETF (SOXL) has reached a record $34 billion in assets, more than tripling since April.

The ProShares UltraPro QQQ ETF (TQQQ) has also grown to around $40 billion, nearing its historical peak.

The pro-cyclical trading mechanism of leveraged ETFs is amplifying market volatility.

Macro strategist Simon White notes that leveraged ETFs inherently possess a "short gamma" characteristic—forced to buy more during rallies and sell during declines.

On some days, rebalancing alone can generate over $50 billion in buy or sell orders, hitting new highs.

Independent proprietary trader Kevin Muir likens the current environment to an "extremely crowded trade" where optimism is deeply entrenched.

"Because of the crazy speculation right now, the next correction could be a lot bigger than people think," Muir warned.

The leveraged ETF asset base nearly doubled in just over two months from late March to early June, reaching a record $220 billion.

Tech-focused leveraged ETF assets grew 136%, while semiconductor-related ones surged nearly 175%.

These funds amplify exposure through total return swaps (TRS), while banks hold the underlying cash equities and re-lend in the repo market, creating a layered leverage chain.

For every dollar of stock, there is now more leverage supporting it.

Dealer Balance Sheets Under Strain: Supply-Demand Imbalance in a $10 Trillion Market

The pressure in the financing market is not an isolated, short-term phenomenon but exposes deeper structural vulnerabilities in the US financial system.

The expansion of dealer balance sheets is lagging far behind the growth in leverage demand.

Even with high-quality collateral, persistently high financing costs indicate market makers' capacity is nearing its limit.

Unless dealer balance sheets expand significantly or stock prices cool sufficiently to reduce financing demand, similar pressures are likely to recur.

The Federal Reserve's semi-annual Financial Stability Report in May explicitly warned it is closely monitoring risks like elevated asset valuations and financial leverage.

The report noted US stock prices are at historically high levels while equity risk premiums are near lows, implying investors are taking on high risk without commensurate expected returns.

Hedge fund leverage remains elevated and concentrated in the largest funds.

The broader shadow banking system is also accumulating risk.

The US banking sector's exposure to hedge funds and non-bank financial institutions has ballooned from about $2 trillion to roughly $4.5 trillion, and the average total leverage of US hedge funds has nearly doubled since 2022.

Goldman Sachs futures trading expert Robert Quinn noted in early July an "unprecedented" spike in stock financing costs, with dealer leverage hitting a mid-year historical peak.

Notably, not all market participants are aggressively adding leverage.

Goldman Sachs prime brokerage data shows the gross leverage of US long/short hedge funds is currently in the 2nd percentile over the past year, and net leverage is in the 6th percentile—hedge funds have rarely been this conservative in the past 12 months.

This suggests the current leverage expansion is led not by professional hedge funds, but by retail investors, leveraged ETFs, and other non-bank institutions.

Systemic Risk: When Rising Financing Costs Trigger a Chain Reaction

Higher financing costs are altering the market's fundamental mechanics.

With a higher "cost of carry" hurdle, leveraged holders require greater stock price appreciation to cover their financing bills.

When banks curtail lending around reporting periods like quarter-ends, they can ration financing by raising fees or demanding more collateral.

This, in turn, could lead to faster selling in the most leveraged market segments during price swings, concentrating declines in the very stocks that initially attracted the leverage.

Market leadership is narrowing as leverage concentrates in hot tech sectors, making the market more fragile to shifts in sentiment.

Macro strategist Simon White warns that record leverage has now extended from retail ETFs and hedge funds into banks and money markets, deeply penetrating the entire system via bank balance sheets.

With bank exposure to hedge funds doubling over four years to about $4.5 trillion, feedback loops could transform banks from market "shock absorbers" into "amplifiers."

Earl expects similar pressures may recur unless dealer balance sheets expand significantly or stock prices cool.

Muir's warning is more direct: "If this is left to run its course, it's going to create a very dangerous environment. The probability of an accident is increasing."

Outlook: High Leverage Meets Earnings Verification, a 'Stress Test' for the Reporting Season

Entering mid-July, US stocks face a critical macro juncture—the Q2 earnings season.

Against a backdrop of high financing costs and crowded leveraged positions, whether corporate profits can justify current valuations will be the core variable testing market resilience.

FactSet data shows analysts raised Q2 S&P 500 earnings estimates by 3.4% during the quarter, forecasting year-over-year profit growth of 23.3%.

Already, 111 S&P 500 companies have issued Q2 EPS guidance, with 57% providing positive guidance.

However, the high-beta nature of leveraged ETFs means any earnings disappointment could trigger a chain reaction—their mechanical rebalancing would amplify the downside.

Goldman Sachs strategists have noted that higher Treasury yields, slowing growth, and doubts about the sustainability of AI profits will limit further valuation expansion.

Bank of America strategist Savita Subramanian believes the S&P 500 faces downside risks in the second half, with pressure stemming from overly high growth expectations and uncertainty around returns on AI infrastructure capital expenditures.

Financing costs and earnings present a dual test.

Changes in financing costs, adjustments by leveraged funds, and marginal shifts in regulatory attitudes could all amplify market volatility.

Current market breadth is extremely narrow—semiconductor and computer hardware companies contributed about 87% of the S&P 500's gains in the first half.

This means if AI leaders' earnings disappoint, highly concentrated leveraged positions could trigger a chain of liquidations.

The quarter-end effect may return: in the upcoming period-end, banks reducing lending to meet reporting requirements typically see repo rates spike, and rising short-term cash costs could trigger a broad pullback in popular trades.

Goldman Sachs's "Tactical Opportunity" Assessment: The bank's quantitative strategists note that leveraged semiconductor ETF assets have dropped sharply by about $53 billion from their peak, and hedge fund leverage is at a near-year low, suggesting systemic pressures are being digested.

As leverage recedes and positioning stabilizes, they see a tactical opportunity to cautiously build long positions in semiconductors and momentum stocks.

However, as Muir warns, in a leverage-driven market, the more entrenched the optimism, the more destructive the eventual correction can be.

With financing costs persistently high, dealer balance sheets strained, and leverage concentrated in a few hot sectors, the US stock market may be brewing a wave of volatility far more intense than it appears on the surface.

When the cost of borrowing to buy stocks surges 200 basis points, leveraged ETF assets approach $200 billion, and margin debt hits a record $1.42 trillion, the US stock rally is no longer just a story of fundamentals.

It increasingly resembles a "leveraged bull market"—where each dollar of gain is supported by more and more borrowed money.

The curse of leverage is that it amplifies gains on the way up and pain on the way down.

As the earnings season curtain rises, this feast built on leverage is about to face a genuine stress test.