Research On Insider Trading And Market Equilibrium,When The Market Deviates From Semi-strong Efficiency

This paper changing the equilibrium conditions of the market semi-strong efficiency,establish a linear equilibrium strategies model.It imports deviation coefficient that is the parameter of the deviation degree of market efficiency.We establish a linear equilibrium strategies model on the market off semi-strong effective to study insider trading behavior,the nature of the market,and the expectation trading volume.Market deviating from semi-strong efficiency is that the market price deviates from the conditional expectation of the asset value on the total volume.So the market price cannot accurately reveal information of the risk asset value.Regardless of the value of the risky asset is overvalued or undervalued,it has a great influence on insiders trading strategy,market properties and trading volume.Compared with risky assets overvalued,when the risky assets is undervalued,insides will expect to gain more abnormal returns,in order to obtain the biggest profit insiders will make full use of its information advantage to actively trade.However,insiders trading behavior is more aggressive.And the market price reveal private information more quickly,and the depth of the market changes faster.In the positive deviation semi-strong efficient market,insiders trading behavior is more conservative,and the internal competitive is small in insiders;with the increase of deviation coefficient of the market expectation volume first increase then decrease.In a word,when the market deviates from the semi-strong efficiency,the trading volume of insider trading is larger and insiders can gain more extra income.At this time,the market depth is less poor liquidity and increases the loss of noise traders.This is not conducive to the fair and impartiality of the market,so as to make the financial market healthy and further development,we should improve the effectiveness of the market.