So, you came here with an extraordinary claim, and when pressed for evidence, you provide one link to a piece with no actual data that reads like something you’d find at jezebel or everydayfeminism, and another that compared how a few hundred female interns at one firm lost less money and were better at following rules than their male counterparts. And we are supposed to take your claim seriously?
Furthermore, imagine the howling and the squealing if a man went to some female-dominated space and said, “Sorry ladies, suck it up, men are just plain better at this thing you all do.” Maybe the evidence is there, maybe not, but that’s not the kind of attitude that is going to encourage meaningful engagement.
Now with that out of the way, I have a very simple answer: as freedom increases for both sexes in a society – as more options previously closed to either sex become available – the sexes self-select into their gender-specific professions anyway, despite all the propaganda and effort to push women into male-dominated spaces (at least the high-paying non-hazardous ones). A light-hearted look at this can be seen here: (I can not post links, but look for “The Gender Equality Paradox - Documentary NRK - 2011” on YouTube.)
It may well be true that women as an aggregate are better at trading than men. That would not be surprising, however, because women in general tend to sit in the middle (or just right of middle, at least in terms of intelligence) of the bell curve, whereas men occupy the entire curve, including the very best and the very worst. (Look for “Men-ARE-brainy-women-says-scientist-Professor-Richard-Lynn” at the dailymail)
Perhaps the higher average intelligence combined with higher levels of diligence do give women an edge in trading. However, the best of the best – genius men who learn diligence – and the worst of the worst are likely going to be men.