Why are world bond markets selling off again?

Global bond yields are surging, with the US 10-year Treasury yield hitting 5.34 percent, its highest since 2002, while French, British, and Japanese yields are also at multi-decade peaks. The selloff reflects concerns over inflation, rising government borrowing needs (US debt has crossed 40 trillion dollars), and a sharp jump in debt issuance to fund AI investments, with five major tech firms issuing 220 billion dollars in bonds this year, more than double last year. Rising yields are squeezing borrowing costs across economies, pushing up mortgage and loan rates, and risk pressuring equities and slowing global growth.