Definitions
Switching into another currency by buying spot and selling forward, and investing proceeds in order to obtain a higher interest yield. Interest arbitrage can be inward, i.e. from foreign currency into the local one or outward, i.e. from the local currency to the foreign one. Sometimes better results can be obtained by not selling the forward interest amount. In that case some treat it as no longer being a complete arbitrage, as if the exchange rate moved against the arbitrageur, the profit on the transaction may create a loss.