UBS' HOLT group has flagged U.S. equities as particularly exposed should a rise in government bond yields start to depress stock prices. In a note to investors, analyst Michel Lerner highlighted a set of forces that have driven sovereign yields upward and said those moves are not yet fully reflected in equity valuations.
Lerner pointed to several specific pressures - the Middle East crisis, ongoing inflation, fiscal strains in heavily indebted nations, and the substantial debt-funding needs tied to the artificial intelligence supply chain - as factors that have pushed government yields back to pre-global financial crisis territory. At the same time, he said, stock market valuations remain considerably more demanding, with U.S. equities standing out.
So far, markets have largely absorbed those macro risks, Lerner noted, rewarding companies that deliver strong cash returns and growth driven by AI-related businesses. But he warned that the current divergence between bond yields and equity valuations may not persist. "History suggests bond vigilante episodes rarely remain contained given the challenges of curbing deficits without weakening growth or fuelling inflation," he wrote.
The note singles out U.S. equities as particularly vulnerable within highly indebted economies. Lerner explained that many companies, especially those within the AI value chain, trade at prices that imply record-setting future cash flows. Such expectations make these stocks especially sensitive to an increase in the cost of capital.
"In effect, this makes the US the longest-duration equity market among developed economies," Lerner wrote, underscoring that higher yields raise the discount rate applied to distant cash flows and thus can more profoundly affect valuations where much of the expected payoff is backloaded.
He also stressed that rising yields increase the hurdle rate for new growth projects - a dynamic that is particularly pertinent for AI infrastructure spending, where the returns are under scrutiny. Against that backdrop, Lerner advised that, in a higher-rate world, investors should prioritise companies with economic moats, robust balance sheets and limited duration risk.
Conversely, he suggested caution toward highly valued firms whose spending patterns outstrip their internal cash generation, as these names are most exposed to an elevated cost of capital and the resulting re-pricing of long-duration equity risk.
Contextual note: The analysis ties together geopolitical, inflationary and fiscal drivers with the capital-intensive nature of AI supply chains to explain why yields have moved and why the U.S. equity market may face outsized sensitivity to those moves.