I place a market buy order with infinity on ES for 3 contracts; The tape(T&S) shows my order executing at 1323.75 but they post a fill at 1324.00 on my account. So I am out 1 tick on the deal. Is this a common practice? thanks
In a market order, YES. When you place a market order to buy and 'see' price at 23.75, in order to buy right away you will more than likely be buying at one tick higher to ENSURE your fill. If price is at 23.75 and a broker puts your order there and price takes off w/o you, then what? Who's at fault now? To avoid that, you just get a fill right away, which means usually taking a tick 'slippage' in terms of what you see as the current price. Only other option is to submit a limit order (hit bid function) on your dom and then you have to hope that you do get filled before price moves away from you. Just the cost of doing business, esp on the ES.