What is Price-to-Book ratio (P/B)?

The price-to-book (P/B) ratio compares a stock's price to its book value per share (net assets on the books). A P/B below 1 means the market values the stock at less than its net assets — often a signal of trouble or undervaluation. Relevant for banks and insurers (mostly financial assets); less relevant for tech (intangibles dominate).