The S&P PMI manufacturing index perked up to 51.3 in the final May reading, up from 50.9 in the May flash, and up from 50.0 in April. Expectations centered on no revision in the May flash at 50.9, which suggests expectations for the May ISM PMI due shortly may tick up from the anemic 49.8 expected.

S&P said manufacturing new orders returned to growth in May, which supported a faster expansion in production. Rather ominously, it said input cost inflation hit a 13-month high.

The final manufacturing PMI for May is expected to come in at 50.9, unchanged from the mid-month flash and 9 tenths above April.

Based on monthly questionnaire surveys of selected companies, the Purchasing Managers' Manufacturing Index (PMI) offers an advance indication on month-to-month activity in the private sector economy by tracking changes in variables such as production, new orders, stock levels, employment and prices across manufacturing industries. The final index for the current month is released roughly a week after the flash.

Investors need to keep their fingers on the pulse of the economy because it dictates how various types of investments will perform. By tracking economic data such as the ISM manufacturing index in the U.S. and the Markit PMIs in the U.S. and elsewhere, investors will know what the economic backdrop is for the various markets. The stock market likes to see healthy economic growth because that translates to higher corporate profits. The bond market prefers less rapid growth and is extremely sensitive to whether the economy is growing too quickly and causing potential inflationary pressures.

The Markit PMI manufacturing data give a detailed look at the manufacturing sector, how busy it is and where things are headed. Since the manufacturing sector is a major source of cyclical variability in the economy, this report has a big influence on the markets. And its sub-indexes provide a picture of orders, output, employment and prices.

Markit originally began collecting monthly Purchasing Managers' Index (PMI) data in the U.S. in April 2004, initially from a panel of manufacturers in the U.S. electronics goods producing sector. In May 2007, Markit's U.S. PMI research was extended out to cover producers of metal goods. In October 2009, Markit's U.S. Manufacturing PMI survey panel was extended further to cover all areas of U.S. manufacturing activity. Back data for Markit's U.S. Manufacturing PMI between May 2007 and September 2009 are an aggregation of data collected from producers of electronic goods and metal goods producers, while data from October 2009 are based on data collected from a panel representing the entire U.S. manufacturing economy. Markit's total U.S. Manufacturing PMI survey panel comprises over 600 companies.