Actually, in poker it is very effective to study and approximate GTO (either by a human or by machine with counterfactial regret minimization).<p>But yes, no one is looking for GTO in trading. The game is not well-defined. There are thousands of participants each with totally different objectives and win conditions. That makes it not zero sum in the first place. Pension funds, banks, HFT firms can all make money while trading with each other.