Game Theoretic Bidding Model: Strategic Aspects of Price Formation at Stock Markets

We consider a simplified model of finance market where two players carry on direct multistage bidding with risky assets (shares). One of the players (the insider) is informed on the liquidation price of a share, the other player knows its probability distribution only. It is shown that the optimal strategy of the insider generates a symmetric random walk of prices of transactions. The result confirms the conjecture on the strategic origin of regular stochastic fluctuations of stock market prices.