Weak efficient market fully reflects the historical trading volume and trading price, and it is invalid to analyze the price trend with technology; The definition of weak efficient market does not point out that it can fully reflect the company's value, macroeconomic situation, insider information and other information, so fundamental analysis is effective and insider information is more effective.

In semi-strong efficient market, fundamental analysis is invalid and inside information is effective; The inside information of strong market is invalid.

In this market, the efficiency of information from generation to disclosure is impaired, that is, there is "inside information", and the efficiency of investors' judgment on the value of information is also impaired. Not every investor can make a comprehensive, correct, timely and rational interpretation and judgment of the disclosed information. Only those professionals who have mastered special analytical tools and high analytical ability can make a proper understanding and judgment on the disclosed information.

1. Weak Efficient Market Hypothesis This hypothesis holds that under weak efficient conditions, the market price has fully reflected all the securities price information in the past, including trading price, trading volume, short selling amount, financing amount, etc.

Inference 1: If the weak efficient market hypothesis is established, the technical analysis of stock price will lose its function, and the basic analysis may also help investors obtain excess profits.

Second, the semi-strong efficient market hypothesis holds that the price has fully reflected all the published information about the company's business prospects. This information includes publicly disclosed financial information such as transaction price, transaction volume, profit data, profit forecast value and company management status. If investors can get this information soon, the stock price should react quickly.

Inference 2: If the semi-strong efficient hypothesis holds, then both technical analysis and fundamental analysis are invalid in the market, and insider information may get excess profits.

Third, the strong efficient market hypothesis holds that the price has fully reflected all the information about the company's operation, including public or internal undisclosed information.

Inference 3: In a strong efficient market, there is no way to help investors get excess profits, even for funds and insiders.