The efficient market hypothesis (EMH) is a financial theory that suggests that asset prices reflect all available information at any given time. According to this hypothesis, it is impossible to consistently achieve higher returns than the overall market because any new information is quickly incorporated into stock prices. EMH is often categorized into three forms: weak, semi-strong, and strong. The weak form asserts that past price movements do not predict future prices, while the semi-strong form states that all publicly available information is already reflected in stock prices. The strong form claims that even insider information is accounted for in market prices.