The Markit/JMMA Japan Manufacturing PMI is a composite index based on five of the individual indexes: New Orders, Output, Employment, Suppliers' Delivery Times and Stock of Items Purchased. The Delivery Times Index is inverted so that it moves in a comparable direction.
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.