Quote from Ghost of Cutten:
But that risk is there whether or not you put in your full position immediately, or wait for a rally to put on your full position. In both cases, once you have on a full position, you have that same 100 basis point (e.g.) correction risk.
Waiting for price action to go your way will mean you wait for people to start recognising what is happening. But if you are right, that is going to happen anyway. And if you are wrong, it won't. So I'm not sure what edge you get from it. Remember, you aren't trading technically here, you aren't saying "I'm buying Aussie rate futures here because they are in an uptrend", you are making a bet on an economic development. In that case, the best risk/reward exists at the time where the market least expects that economic development to happen, not at the time that it starts pricing in a significant probability of it happening.
A good example is the Euro. The best risk/reward was at 1.45, 1.50, when people were still expecting a weaker dollar, and were overlooking the sovereign debt risks in the Eurozone. Now at 1.23 the upside is 20-25 big figures less, and the risk is at least as much (we just had a 5 handle move in 2 days, whereas at 1.40-50 it took a week or two to move that far).
For fundamentally-driven trades, waiting for a trend to get going results in higher risk and lower reward, and doesn't in any way improve the probability of you being right about the ultimate outcome - every time the market "starts rallying" it could just as likely be a short-term blip in a long trading range, or even a sucker rally before falling back down. Now if you are using a trend-following system with a close trailing stop, it's a different matter. But that is a technical system not a fundamental one. And it substitutes one risk for another - you adopt the risk of ultimately being 100% right, but losing money by being stopped out 3 or 4 times in a row on short-term pullbacks.