The market-to-book ratio is a financial metric that compares a company's market value to its book value, calculated by dividing the market price per share by the book value per share. This ratio helps investors assess whether a stock is undervalued or overvalued by comparing its current market price to the net asset value recorded on the balance sheet. A higher ratio often indicates that investors expect future growth, while a lower ratio may suggest the opposite, providing insights into how the market perceives the company's worth relative to its actual asset base.