[Cdawg]

I understand what margin is used for, but I'm confused how margin plays in gains & losses.

For example:

100:1 leveraged account
1 standard unit = $100,000 correct? No, 1 standard lot is 100,000 units, price is equvalent to the currency your trading

200:1 leverage account
1 standard unit STILL = $100,000 correct? to keep it simple yes, though only 1/2 as much margin is required for the 100,000 units
So when booking a P/L, they are both the same. Margin plays a roll in how much of your own money you put up, not increases or decreases the $ of your P/L. What it does do is increase/decrease your Cash-on-Cash% return, giving you a larger +/- ROI%. I think that is upto you on how your evaluate your own ROI, if you look at it as in (100:1) i put up $1K to make $x or i put (200:1)up $500 to make the same $x then you would be correct.

Am I correct in this?

Margin plays a factor in your profit/loss because as you increase the amount of lots you use, the margin increases.

Your lot size should be determined by your calculated risk i.e. 1%, 2% or what ever you choose, therefor utilizing 100:1 or 200:1 or 50:1, your lot size should be the same and the amount of margin should be a non factor, the only real difference is that the higher the leverage, the more useable margin you will have in your account