I look at in terms of dollars/euros/yen/etc allocated. Virtually all of this money is allocated by pension funds, mutual funds, sovereign wealth funds, and si

I look at in terms of dollars/euros/yen/etc allocated. Virtually all of this money is allocated by pension funds, mutual funds, sovereign wealth funds, and similar behemoths. They may be using ML to improve their execution -- more likely they've outsourced execution to third parties who use ML -- but they are _not_ using ML to make the capital allocation decisions. Nor are they profiting significantly from short term arbitrage opportunities. Capital allocators worth mentioning generally are handling trillions of dollars. The largest arbitrageurs are incapable of handling more than $10-20 billion. This is rounding error in the world of capital allocation. EDIT: The 50%+ figures you're quoting measure daily trading volumes, which is not the same thing as capital allocation. Most of those traders don't hold positions overnight; they don't do capital allocation. (Imagine how a startup founder would feel if his investors took away their invested cash after 5pm every night.)