The S&P Global South Korea manufacturing PMI's headline index was little changed in October, easing to 49.8 from 49.9 in September, indicating that activity in the sector remains weak but has stabilised. Respondents, however, report improvement about the outlook for demand over the coming 12 months.

Survey respondents reported output, new orders and new export orders all fell at a steady and modest pace in October. Payrolls were again reported to have risen in October and the survey's measure of business confidence improved after falling to a three-month low in September. Respondents reported input costs rose at a faster pace in October and that they increased selling prices for the second consecutive month.

The Purchasing Managers' Manufacturing Index (PMI) is based on monthly questionnaire surveys of selected companies which provide an advance indication of what is really happening in the private sector economy by tracking changes in variables such as output, new orders, stock levels, employment and prices across the manufacturing sectors.

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.

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.