Rates held steady early Wednesday, although mortgage-backed securities came under pressure following the release of stronger than expected economic data. The Institute for Supply Management manufacturing index rose to 56.3 in August from 55.5 in July. A reading of 53.0 had been forecast. Readings above 50.0 indicate expansion in the manufacturing sector. Construction Spending declined by 1.0%, close to expectations. The Mortgage Bankers Association weekly purchase activity index rose 2%, while the refinancing activity index rose 3% to the highest level since May 2009. Average reported rates for 30-year fixed mortgages fell to 4.43% last week, excluding fees. No other data will be released today.