Nassim Nicholas Taleb warns falling Treasury demand could hurt stock rally

A pullback in demand for U.S. Treasuries could jeopardize the stock-market rally, the "Black Swan" author Nassim Nicholas Taleb said in an interview with Bloomberg. “The bond market is very vulnerable,” Taleb said, adding that the U.S. must finance its budget deficit through investors who may become less willing to fund it.

He echoed concerns raised by billionaire Ray Dalio that the rising cost of servicing U.S. government debt could test demand for Treasuries. However, Taleb sees weakening demand from domestic investors as the greater risk. He fears that U.S. retirees and funds pulling back from long-duration debt would deal a more serious blow to the market than waning demand from major creditors such as China or Japan, which Dalio warned about this week.

Yields on long-dated U.S. government bonds are at 24-year highs, making the outlook for the debt market particularly challenging, Taleb noted. He said this creates a potentially dangerous divergence between buoyant equities and growing vulnerabilities elsewhere in financial markets. The S&P 500 closed at a new all-time high on Tuesday for the first time since August.

Taleb stopped short of predicting a stock-market crash. He said it is more important for investors to recognize that the market is becoming increasingly fragile and can remain expensive and continue rising until an unexpected event exposes accumulated risks. “It’s false to think in terms of the market will go down,” Taleb emphasized. “You think in terms of risks increase.” The appropriate response is not necessarily to turn bearish but to structure portfolios so that they can withstand an unexpected shock, he said.

Taleb also cautioned against assuming that the tech companies currently leading the market will be the ultimate winners from the AI boom. It would be “a trap to go invest in companies” that benefit from AI simply because the technology is changing the world: looking back, “the companies that benefitted were not the pioneers,” he noted.

He also questioned whether the S&P 500’s performance reflects the health of the U.S. economy. The index’s largest companies are global businesses, he said, meaning their performance does not necessarily reflect the financial condition of American households. Investors should pay more attention to the experience of middle-income families than to the level of the stock market, Taleb believes. “Always have a tail hedge, even if you have no reason to hedge,” Taleb concluded.

So-called tail risks are extremely rare events with devastating consequences. In his 2007 bestseller, Taleb popularized the equivalent concept of “black swans” – events that initially appear unlikely but often seem entirely logical in hindsight after they occur. Taleb later also raised the concept of a “white swan” to describe an obvious risk that the market ignores until it is too late. In 2025, he identified the growing U.S. debt as one such risk.