The Price-to-Book (P/B) ratio is a financial measure used to compare a company's market value to its book value. It is calculated by dividing the market price per share by the book value per share. A P/B ratio below one can indicate that the stock is undervalued, while a ratio above one may suggest the market is willing to pay a premium for the company's assets. The ratio is beneficial for assessing companies with significant tangible assets. However, it can vary across industries.
