Quote from cabletrader:
No, it's much easier, and you can adjust trade size up and down according to account balance. The more you lose, the smaller the trade size. The more you win, the larger the trade size. It's much more versatile.
Another benefit is you can work out trade size exactly, based on your stop and equity. Stops vary from trade to trade as we know, therefore trade size has to change to stay within your risk parameters.
eg:
Account balance $12,849.63
1% = $128.50
Stop for this trade 23 pips
$128.50/23 = $5.59 per pip, trade size $55,900
Let's say you win that trade and make $210, your account is now $13,059.63.
This trade doesn't look great so you might only want to risk .5%, and your stop needs to be wider at 28 pips and as there's data coming out Oanda are widening spreads to 20 pips so the stop has to be 48 pips:
Account balance $13,059.63
.5% = $65.30
$65.30/48 = $1.36 per pip, trade size $13,600
no i meant it was hard to remember that 0.0083% isnt the same thing as 0.83%, which i thought. Does oanda by the way, have widening spreads to 20? Thats only during news?