A popular market structure that has fueled the S&P 500’s rally past 7,500 points now poses a significant threat, creating what one strategist calls a "death spiral" waiting to happen.
The U.S. stock market’s powerful rally is built on a mechanical flaw that could trigger a $187 billion wave of forced selling if the S&P 500 drops just 5 percent in a single day, according to a new warning from Nomura strategist Charlie McElligott.
"This is just making the cliff that we will eventually de-lever off of that much higher," McElligott said in a recent client note, describing a scenario where the mechanisms that create buying pressure on the way up would aggressively sell into a downturn.
The core of the risk lies with options dealers and a $179 billion complex of leveraged exchange-traded funds, 85 percent of which are concentrated in high-flying technology, AI, and semiconductor names. These products have been a primary driver of the recent rally, with leveraged ETFs alone accounting for over $100 billion in net buying over the past month.
The dynamic, known as "negative gamma," creates a self-reinforcing cycle where a market decline would force these systematic strategies to sell assets to rebalance their portfolios, amplifying the initial drop. This structural risk is emerging as long-term interest rates climb to their highest levels since 2007, providing a potential macro trigger for a correction.
McElligott’s analysis highlights the unprecedented scale of leveraged ETFs and their role as a source of "synthetic negative gamma." In a rising market, these funds must buy more of the underlying assets to maintain their targeted leverage, which has recently added billions in daily buying pressure, particularly in the semiconductor sector via ETFs like SMH.
However, the process works symmetrically in reverse. A significant market drop would force these funds into a massive wave of selling to reduce their exposure. McElligott’s model calculates that a 5 percent single-day decline in the S&P 500 would compel options dealers, leveraged ETFs, and volatility-control funds to collectively dump an estimated $187 billion of equities into the market, creating a "sell-off vortex."
While market structure provides the fuel, rising interest rates could be the spark. The yield on the 30-year U.S. Treasury recently climbed to its highest level since August 2007, a sign that bond investors are demanding higher compensation amid sticky inflation and a surprisingly robust U.S. economy.
McElligott notes that with nominal GDP growth running near six percent and inflation proving stubborn, the risk of higher-for-longer rates is re-emerging as a major headwind for equities. He warns that rising interest rate volatility, measured by the MOVE index, could soon reassert itself as a primary factor suppressing stock prices, providing the macro shock needed to initiate the de-leveraging event. The strategist points to the period after the upcoming monthly options expiration as a potential window for this reversal to begin.
This article is for informational purposes only and does not constitute investment advice.
