Rental Arbitrage is a smart technique to earn money in any type of property including a multifamily house, duplexes, or triplexes. Arbitrage is the simultaneous purchase and sale of the same asset in different markets in order to profit from a difference in its price.Arbitrage is the simultaneous purchase and sale of an asset to profit from an imbalance in the price. To put it into context, arbitrage is when a trader buys and sells an asset at different locations, at the same time. Arbitrage is the process of simultaneously buying one instrument and selling another security short (also known as shorting a security) Arbitrage is the process of simultaneously buying and selling the same asset or security in different markets to take advantage of price discrepancies.