According to the following trends of Taiwan stock weighted index, the turning points amid the bearish and bullish markets are derived from the weekly charts of the indices combined with the multiple time series. In this study, we analyze the timing for the private investors to purchase several stocks under the risk exposure based on the trading volumes and PE ratios. Like the game theory, we try to find a useful method for investors to beat the market to get twenty percent rate of returns. For the fixed costs, the portfolios will be adjusted by the psychology and the irrational actions of the market participants. Actually, the weekly charts of the prices always reflect the trends upwards or downwards. Here, The risks control of and crisis management for the investors based on Buffet’s strategies during the periods of the bearish market and incident events are needed in his study.