Stock market investors develop different strategies to improve the profitability of their investments. The investment strategy studied in this case is value investing, which consists of investing in undervalued stocks and then selling them at a higher value, their fair value. Indeed, even though the market price is supposed to already include all available information according to Fama's theory of efficient markets, behavioral finance shows that investors can behave irrationally, leading to an overvalued or undervalued market price.