The efficient market hypothesis has been one of the main topics of academic research on finance. Efficient market hypotheses, also known as the joint hypothesis problem, state that financial markets lack solid, concrete information in making decisions. The efficient market hypothesis states that it is impossible to beat the market because the efficiency of the stock market causes existing stock prices to always incorporate and reflect all relevant information. According to the efficient market hypothesis, stocks always trade at their fair value on stock exchanges, making it impossible for investors to buy undervalued stocks or sell stocks at inflated prices. Therefore, it should be impossible to outperform the overall market through expert stock selection or market timing, and the only way an investor can achieve higher returns is to purchase riskier investments. In reality, it is not always possible to achieve returns above the average market return on a risk-adjusted basis. There have been numerous arguments against the efficient market hypothesis. Some researchers highlight the fact that financial theories are subjective, in other words they are ideas that try to explain how markets work and behave. The Efficient Market Hypothesis was developed by Professor Eugene Fama at the University of Chicago Booth School Of Business as an academic concept to study through his published Ph.D. thesis in the early 1960s. Fama proposed in his thesis two crucial concepts that have defined the debate on efficient markets. The efficient market hypothesis was the most important theory in the 1960s, Fama published a thesis arguing the random walk hypothesis to support his efficient market theory. “Fama has demonstrated that the notion of market efficiency… is at the heart of the charter… of the public and private sectors. Use both the weak and semi-strong forms to make decisions. When an investor is given both public and private information, the investor would not be able to profit from the average investor even if they were given new information at any given time. These investors are given a name as insiders, foreign exchange specialist, analyst and money managers. Insiders are senior executives who have access to that company's inside information. The Security Exchange Commission prohibits the use of inside information to obtain abnormal investment returns. A stock specialist can achieve above-average returns with specific order information on a specific stock. Analysts can analyze whether an analyst's opinion can help an investor achieve above-average returns. Institutional money managers manage mutual funds and pensions.