Hey Casa Mania,

You asked a really excellent question. I am an active trader and 100 round turns per day is not unusual for me. That adds up comission wise, like 500 bucks most places I trade. But I suspect there is more below the surface?

You and I as retail traders, we trade quarters. In other words, if we are trading the ES we are filled at 00, 25, 50, or 75. Our brokers are trading the bigs, which are filled in dimes, in other words their orders are filled at 00, 10, 20, 30, 40, 50, 60, 70, 80, 90.

So, this means that when you place your limit order at "say" something .50, your broker will not fill you unless he is able to "offlay" your position at his dime less or .40. Then he fills you and he has your dime in his pocket.

Anybody who has traded for a long time begins to realize this is not a fair game.

Essentially you as a retail trader are at the mercy of your broker. "If your broker fills you at one tick less or more how would you know?"

My only good advice is too "Trade on a SIM account for at least 3 months."

I hope more experienced traders will correct any errors in my answer to Casa Mania's question.

I wanted to point out that as "retail" traders we trade against professional money.

please feel free to disagree with me, as I am often "WRONG"