The "Strong Form" of the Efficient Market Hypothesis (EMH) asserts that all information, both public and private, is fully reflected in asset prices. This means that no investor can achieve consistently higher returns than the market average by using any information, as it is already incorporated into the stock prices. In this form, even insider information is considered useless for gaining an advantage. Proponents argue that since all available information is accounted for, it is impossible to outperform the market consistently. This theory challenges the effectiveness of strategies like technical analysis and fundamental analysis in generating excess returns.