Stocks closed April at records. But something's happening that could break the boom

Just as investors in April looked past the effect of the U.S.-Iran war to focus instead on a reignited artificial intelligence trade and strong corporate profits, a warning signal came from the bond market. On Thursday, the 30-year U.S. Treasury bond yield briefly rose above 5%. In early trading Friday, the 30-year yield stands at 4.979%. …