PEAD, or Post-Earnings Announcement Drift, refers to the phenomenon where a company's stock price continues to move in the same direction after an earnings announcement. This occurs as investors gradually react to the new information, leading to a delayed adjustment in the stock price. The effect is often observed in the context of financial markets and can be attributed to factors such as investor sentiment and the time it takes for analysts to revise their forecasts. PEAD challenges the efficient market hypothesis, which suggests that stock prices should immediately reflect all available information.