A broad selloff in global bonds is driving borrowing costs higher for governments, companies and households across developed markets, with yields reaching 19-year highs. Wall Street sees little immediate relief. Investors are linking the pressure to several forces at once: the continuing U.S.-Iran conflict, which has fueled inflation concerns; a wave of tech-company bond sales competing for fixed-income demand; worries over budget deficits; and limited clarity from a new Federal Reserve chairman. Rising bond yields generally mean falling bond prices and more expensive financing across the economy.