Originally posted by Reitberg
I trade E-minis S&P 500s. I make about $1500/day and I usaully only have to do about 30 RTs a day. When I have a bad day though, My RTs can be like 200. I use interactive brokers. I may get shot down for this post, but my real objective is to make money everyday. My first month out of school, trading on my own has been good, but now I'm realising that there has been too much risk at times. I think as my trading gets better, I'd settle for about $500-$1000 a day in profits and only trade about 5 contracts at a time. and keep my RTs below 50 a day.
So I guess the answer to your question is that it depends on how much you pay your broker. At my current level of RTs, I've been offered some pretty good deals from clearing firms, even though I don't have a seat yet. I'm kind of at that point where getting a seat is a toss up. I think the best deal in seats right now may be with the mini-size Dow futures.
Another thing is that you should never do any trades that you are not mechanically able to take on. Like, if you have a good day, don't start swinging for the fences and trade 20 contracts at a time. It sounds like a good deal to scalp for .25 point but it can be disatrous when it the S$P moves a point against you.
My general rule of thumb is to keep trades to 10 minis at a time when you are confident and 5 minis for when you are not as sure, like during an 8:30 AM announcement and you can't find the proper supports to play on.
I hope that this helps. I it so hard to give a really good answer to your question. Perhaps they only way you will figure it out is going through a lot of pain before you can become truely confident about a proper size.
Good luck to you.