One big reason for the big rise in bond yields? More evidence that inflation risks persist.

U.S. business activity growth accelerated to its highest rate in over five years, according to S&P Global U.S. PMI data released this morning. But higher September growth, partially driven by higher manufacturing output, comes as supply chain delays and spikes in energy prices place upward pressure on inflation.

Manufacturing and services activity rose to 57 and 58.7, beating the expected 53.5 and 55.7 numbers by economists polled by the Wall Street Journal.

Price pressures ticked up in September, largely on higher fuel and shipping costs. Input costs, while higher, remain below their peaks from the initial months of the war in Iran.

"Firms' input costs have meanwhile jumped in September at the steepest rate for four years, with fuel and transport costs spiking higher thanks to the rise in oil prices seen during the month, which will add further to the upward pressure on selling prices and inflation in the coming months," said Chris Williamson, chief business economist at S&P Global Market Intelligence, in written comments.