Updated

Yields across global bond markets, including the more than $30 trillion U.S. Treasury market, have risen sharply over the past few months, with September marking one of the worst months for bonds in a generation. Strategists note the move has been unusually fast and broad, unsettling investors who worry that rising borrowing costs could eventually spill over into equities. Some analysts, including those at BofA Global Research, argue that the real risk to stocks isn't the bond selloff itself but the potential unwinding of the so-called 'AI put' — the market's assumption that heavy AI-related capital spending will keep underpinning equity valuations. Commentators warn that if history is any guide, October could bring even more volatility for fixed income than September did.