Changing the default source for one instrument is useful if multiple sources use the same symbol for different instruments. For example, getSymbols("CP", src = "yahoo") would load Canadian Pacific Railway data from the New York Stock Exchange. But getSymbols("CP", src = "FRED") would load Corporate Profits After Tax from the U.S. Bureau of Economic Analysis.

You can use setSymbolLookup() to specify the default data source for an instrument. In this exercise, you will learn how to make getSymbols("CP") load the corporate profit data from FRED instead of the railway stock data from Yahoo Finance.

setSymbolLookup() can take any number of name = value pairs, where name is the symbol and value is a named list of getSymbols() arguments for that one symbol.