He's actually right gambino, market orders are for people in a hurry, limit orders are for those with time to spare.They also can prevent downside risk, see here:"Many beginner traders assume the limit order trade means to only buy a stock when it falls below a certain price or only sell a stock when it goes above a certain price. They feel that the limit order is like the autopilot function, so that if they are away from their computer, trades still go through. Therefore, the use the market order under the false belief they are making better trades, because they buy or sell right away.However, there is one important function of the limit order that many beginner traders fail to notice. This function of the limit order is protecting the price of the realtime trade you make. There is no rule saying a limit order has to be below the current stock price. What if you set the limit buy order just a few cents higher than the current market price? You would still get in immediately as with a market order.The limit order is not just a function to get a good price, but also to protect yourself from sudden market crashes. During the flash crash of May 2010, Proctor and Gamble's stock dropped over 30%. One trader not knowing that the flash crash was happening dumped his stock in a market order at the peak of the crash. Had he just waited a few minutes, then he would have recovered most of his losses. The solution is when you buy a stock and want to get in immediately, set the limit order a few cents above the current market price. If you sell a stock, set the limit order a few cents below the market price. That way, you can still catch fast market opportunities while protecting yourself from extreme losses."I'd argue that Limit orders are actually more useful in a volatile market environment. It doesn't matter whether we're talking stock, commodity or currency including the B$, the same rules apply in all markets.