Arbitrage is to invest in the market, to use its own funds and not have to bear any risk situation, by simultaneously buying and selling financial instruments acquired behavior remuneration. Arbitrage type also includes simultaneously buy and sell the same product in different delivery months, or buy and sell the same delivery month of the same commodity in different exchanges, or in the spot market and the futures market to buy and sell the same product at the same time . Arbitrage is to adjust the exchange rate around, it tends to balance supply and demand of foreign exchange and promote the regional balance function. In short, arbitrage is referring to the same securities traded on multiple markets, pocketing the difference as profit.