The ISM Services Purchasing Managers' Index rose to 53.4 in January, a 13th straight month of expansion in economic activity in the services sector, data released Monday showed. The prices index in January was at 64, a 7.3-percentage point increase from December’s seasonally adjusted reading, according to the Institute for Supply Management report. The strong data adds to evidence of the US economy's resilience that could pose upward pressure on consumer prices.