Some traders have probably noticed that speed of quoting at different forex brokers often differs. The reason for this may be: feed aggregation from different liquidity providers, such as banks, or broker’s cheating, such as quote feed smoothing. The gist of arbitrage on market is as follows: buy a thing, in our case a currency pair, cheap and imediately sell it for a higher price, profit being the difference of prices. Of course, one can get profit from such arbitrage only if this difference is higher than brokers’ spreads and commissions combined. Such operations are called classical (bipedal) arbitrage. The main advantage is the absence of risk, so it has zero drawdown. If one dealer quotes are always delayed to the other, it is better to use one-leg arbitrage, where orders are only sent to the broker with its quotes lagging.