Percentage wise he made less than 0.40%!!! The Nikkei stock exchange went up 57% in 2013 in Japan but he only made 0.40% (yes, you see that correctly, less than half of one percent) so no I will not back down from my statement that he is an idiot with ADD. The article does not state how big his trading account is so I had to use the $15 billion total figure for my calculation but nonetheless I'm safely assuming that he must be trading with a few hundred million dollars alone to reach trillions in trading volume.
Why is that a safe assumption? 15000000 / 54000000 = ~278. Thus one 54 million trade a day is way more than enough to get high trade volume. 41 trades one million dollar each a day would also be enough. I would guess the actual trade amount would be somewhere between those values.
Unless I managed to fail my calculations.