Special Session 147: From optimal control to large population games: Learning and Applications

Relative Arbitrage in an Extended Mean Field System
Tomoyuki Ichiba
University of California Santa Barbara
USA
Co-Author(s):    Nicole Tianjiao Yang
Abstract:
We consider relative arbitrage opportunities in a market with competitive investors through stochastic differential games in the limit as the number of players tends to infinity. We explore a conditional McKean-Vlasov system to study the market dynamics coupled to the expected trading volume of investors, and characterize optimal arbitrage in terms of the volatilities. Here, the mean-field interaction is considered through a joint distribution of wealth and strategies. In this setting, the optimal relative arbitrage constitutes the strong equilibrium of an extended mean-field game. We provide conditions for the existence and uniqueness of the mean-field equilibrium. We further prove the propagation of chaos result for the finite-player game counterpart, and demonstrate that the Nash equilibrium converges to the mean field equilibrium when the population grows to infinity.