The sell-off in US Treasuries continued as the 30-year yield (the annual return on long-term government debt) moved above 5.4%, reaching a fresh 22-year high. Market expectations for additional tightening by the U.S. Federal Reserve (the US central bank) surged, sending all major US stock indexes lower in early trading on Thursday, Sept. 24. The source also identifies the Philadelphia Semicon among the affected market indexes, but the provided text ends before its full name or performance is stated.