DislikedFj would be your best bet to answer your question.
I would think it depends on the positions you have open at the time.
By taking the second short trade you might be able to balance your risks better if you are already overly geared with your open postions towards long AUD and short USD.
On the other hand if your open positions are already on balance short AUD and long USD, I wouldn`t take this trade.
Its all about MM.
Another thing you might take in consideration is the trend in the pair.
If you`re wrong in your trade but trade in the direction of the trend, the trend might bale you out.
So if I would like to take a second trade in a pair, I would be more inclined to enter a second trade long from 20% in this pair AUD/USD.Ignored
DislikedI wouldn't have a problem with this approach. As long as doubling up on a trade also decreased your overall exposure risk to a currency you might be overexposed to.Ignored
This is one area where we differ, Flyjetz. I know you are trading something like 27 pairs. I have chosen a select set of 10 pairs. It is my hope that this set of pairs is highly diversified in the sense that there is low correlation between the pairs involved. For the major pairs in my set of 10, I was able to find correlation data, so I have some basis for choosing them. For the more exotic crosses, I simply chose currencies that seemed to be economically unrelated, but it was just a guess really. Ideally, e.g. a large drop in EUR/CZK won't necessarily lead to a large drop in EUR/USD. I will just have to see how it goes, see if these 10 move more or less independently of each other.
Along the lines of position sizing and exposure, I've been thinking about carry trades. Some times you will be holding on to a trade for a while and updating the TP every week as you wait for it to be hit. With such a long exposure, the carry interest can really add up (or down). It's great when you're on the right side of the interest rate differential, but it's terrible when you're on the wrong side. So I was thinking of trading a little heavier when the position lines up with the interest rate differential, and a little lighter when it's against you.