When does a commission become excessive?

Let's say my average trade makes $100. Would $5 for example be a good commission (5% of what I win)? And what would be the maximum acceptable commission in terms of % of profit?

A commission is the cost of doing business, same as a spread. Major corporations may make 5 - 15% a year after paying expenses. It seems to work for them.

Long-term traders will say they pay a smaller percentage to trade, while scalpers pay much more, but they have more opportunity to trade. To each their own.

Only you can answer how much you're willing to pay.

Don't worry about commission. Make trades that go from your initial position to at least 0 or greater pips. Figure out how to do that, and your set.

When it becomes a commission.

Unless you are getting true STP (rare among pure Retail), then they are:

1) Trading against you.
2) Generating revenue on the spread.
3) Generating revenue on the commission.

At a 90% failure rate among the typical Retail'er, that's three different revenue streams. At the very least, that's an approximate 78% probability of revenue being generated 33.9% of the time and 100% probability of revenue being generated 66.9% of the time. They get their cake and they get to eat it, too.

That's one heck of a revenue expectancy model. Nice work, if you can find it. Right now, there are plenty of places the Retail'er can go, without having to pay a dime in commissions. Just do your homework.