I do not think that machine gonna dominate the market. The main strength of the computers is their main weakness: They´re mechanical.
Human eye and mind had evolved trough a lot of time to adapt to dangerous environments trough recognizing patterns that lead to a possible danger. And machines are pretty limited in their patterns, even a random number generator has a pattern that can be recognized if you afford the energy and the time to it.
If the market become 100% automatic, there will be no chaos in there, the number of patterns would be limited to the number of minds that program the computers.
Another thing, machines can defeat us only in an environment with known conditions and a limited number of possible variables (like chess). The market is one of the most unlimited environments, if you have the mind and the power (financial), you will win out there.