Strong Form Efficiency The strongest version of market efficiency. It states all information in a market, whether public or private, is accounted for in a stock price. Not even insider information could give an investor the advantage. Investopedia Says: This degree of market efficiency implies that profits exceeding normal returns cannot be made, regardless of the amount of research or information investors have access to. Related Terms: Efficient Market Hypothesis - EMH False Market Fundamental Analysis Random Walk Theory Semi-Strong Form Efficiency Technical Analysis Weak Form Efficiency |