Indexing is used in the financial market as a statistical measure for tracking economic data. Indexing is also used to refer to passively investing in market indexes to replicate broad market returns rather than actively selecting individual stocks.In investing, indexes become performance benchmarks against which portfolios and fund managers are measured.In economics, indexes can directly impact people's livelihoods, for example in the form of cost-of-living adjustments that are indexed to inflation.There are many indexes in finance that reflect on economic activity or summarize market activity.Indexing is the practice of compiling economic data into a single metric or comparing data to such a metric.