Quote from Cutten:
What do you think about my point of getting into a "good run"? He talks about starting tentatively, constantly reexamining mistakes, and then if he gets on a good run with decent profits, he becomes more aggressive. Could this refer not so much to a psychological issue about the gains/principal fallacy, but rather the extent to which Soros feels "in the zone" and in tune with market moves and developments? If he is analysing things accurately, and trading well, profit will accrue - thus he can use profit as a signal that he is trading well, and thus to trade much bigger than normal. Equally, if he sucks and is making bad trades, it's best for him to be trading small.
I don't know if Soros does this consciously or subconsciously (e.g. by using the gains/principal fallacy as an accidental way to trade his own hot streaks more aggressively), but it seems to work and make logical sense.