Trading success isn't biased against skin color. But trading success is biased against black (african) genetics. I am pretty sure of that.
In the same way black people have genetic advantages over non blacks for many sports. And they win.
There are always exceptional outliers.. But black people in general didn't win the genetic lottery when it comes to trading.
I would guess the Jews won that lottery.
Same for women. I would guess female genetics makes them more emotional and less risk seeking than men. And those are definite disadvantages when it comes to trading. Again this is a general observation, many women will still be great traders, just nowhere near in the numbers that men are.