What is an Arbitrageur?

A type of investor who attempts to profit from price differences within the market by making concurrent trades that counteract each other and acquiring risk-free income. A stock market arbitrageur would hunt for price discrepancies between stocks listed on more than one exchange, and purchase the undervalued shares on one exchange while short-selling the equivalent number of overvalued shares on another exchange, procuring risk-free profits as the prices on the two exchanges come together.