Ok - sorry: I may slightly have misunderstood your original question (“overtrading” usually means “entering trades too often”, but I see now that you’re referring to total simultaneous risk-exposure!) :8:
I see your point: it’s easy to do this inadvertently, with forex, since currency-pairs tend all to be to some extent correlated (either directly or inversely, so it matters which?). That mostly depends on your position-sizing, i.e. risk of loss in proportion to your total account-size.
For myself, I never have more than a total of 1% of my account at risk at any one time. So if I’ve added another 1% to a winning position (which I sometimes do) it’s only after moving the stop-loss enough for only that most recently added 1% to be at risk.
I’m not saying that the “1%” is an immutable figure that should apply to everyone else too, of course (that will depend on the size of their “edge”), but I think the principle’s valid, in that you shouldn’t expose to risk at the same time more than whatever proportion of your account meets your own risk-management parameters, degree of risk aversion, acceptable drawdown, and so on. (For myself, my blood would freeze and I might collapse, if I ever had a drawdown bigger than 5% of my total account, and even that would be very hair-raising and unpleasant indeed.)
Depending on your trading style, of course, it may be possible to mitigate the risk. For example, if you’re trading GBP/USD and USD/CHF at the same time, either both long or both short, that [B]reduces[/B] risk because the two pairs are inversely correlated (i.e. you’re effectively long on the USD in one trade and short on it in the other), whereas if you’re trading USD/CHF and USD/JPY, both long or both short, at the same time you’re [B]increasing[/B] your risk, because changes in the value of the USD will have more or less a double effect on your situation. In short, it’s all a little bit more complicated than it looks.
In short - there’s nothing wrong [B]in itself[/B] with having 9 trades open, but if you’re actually risking, say, 9% of your account at a time, that may be [U]terribly[/U] dangerous.
Sorry if I haven’t answered your question very helpfully, here! :8: