Mortgage rates were steady to slightly lower Wednesday in light trading. In economic news, the Chicago Purchasing Managers Index, a measure of manufacturing activity, jumped to 60, well above the consensus forecast of 55. A reading above 50 indicates expansion in the manufacturing sector. The mortgage-backed securities (MBS) market will close early tomorrow in observance of the New Year’s holiday. Next week may be volatile, with several key reports due to be released, beginning with the ISM manufacturing index on Monday, minutes from the December FOMC meeting of the Fed on Wednesday, and the Employment Report for December on Friday. No other data will be released today.