The final composite is expected unrevised at 50.1 in the final report for December from the flash and down from 50.4 in November. The final services index is expected unrevised from the flash at 50.2 in the final report for December and down from 51.4 November.

The Composite Purchasing Managers' Index (PMI) provides an estimate of private sector output for the preceding month by combining information obtained from surveys of around 750 manufacturing and service sector companies. Results are synthesised into a single index which can range between zero and 100. A reading above (below) 50 signals rising (falling) output versus the previous month and the closer to 100 (zero) the faster is output growing (contracting). The report also contains the final estimate of the services PMI. The data are provided by S&P Global.

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 purchasing managers' manufacturing indexes, 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.