DislikedRe the earlier comments on average ROI, I suspect that much depends on the type and accuracy of one's system, the timeframe being traded (scalping, intraday, swing trading, position trading, etc), and the position sizes. By the latter, while I realize that forex is completely scalable, I mean that a small retail trader should easily be agile enough to avoid liquidity problems, while a large bank or fund moving vast sums might need to unwind positions more slowly. I don't know to what extent that's true, but I've read that, despite the size of the forex market, liquidity can become an issue for the really big players.
A retail trader who is trading intraday will get the opportunity to compound his gains (and losses!) quickly. Assuming his method delivers a genuine edge, I don't see why returns well in excess of 20%-30% per year shouldn't be easily possible. If I didn't believe so - then for me, persoinally - there would be little point in pursuing a career as a trader; I'd need to start with a $200-$300k (that's NZD, I live in NZ) account just to make a reasonable annual income. And possibly more so, IMHO, to justify the time and effort, and levels of stress, involved. With interest rates in this part of the world being so high, it's not too difficult to find low(ish) risk passive investments that return 8%-10% here.
DavidIgnored