Price-to-Book Ratio (P/B)

Price-to-book compares what the market is willing to pay for a company against the accounting value of its net assets. It is one of the oldest valuation metrics, central to Benjamin Graham's approach and the Fama-French value factor.

A P/B below 1.0 means the stock trades at a discount to book value - the market prices the company's assets below their balance sheet carrying value. This can indicate a bargain or signal that assets are impaired, obsolete, or overvalued on the books.

The 1994 Lakonishok, Shleifer, and Vishny study confirmed that low price-to-book stocks (high book-to-market) systematically outperform high P/B stocks over long horizons. This finding remains one of the most robust results in empirical finance.

Lower P/B ratios suggest cheaper valuation relative to assets. Graham required a P/B below 1.5 (or P/B times P/E below 22.5) for his defensive investor criteria.

P/B is most meaningful for asset-heavy businesses - banks, insurance companies, real estate, industrials - where book value approximates the replacement cost of the business. For asset-light companies (software, consulting, brands), book value understates true economic worth because intangible assets like intellectual property and human capital do not appear on the balance sheet.

Stock buybacks funded by debt can reduce book value to near zero or negative, making P/B meaningless for companies like McDonald's or Starbucks that have repurchased more equity than they currently carry.

Banks and insurance companies are most commonly valued on P/B because their assets (loans, securities) are marked to market or close to it. A bank trading at 0.8x book may be a genuine bargain; one at 1.5x book is pricing in above-average returns on equity.

For technology and pharmaceutical companies, P/B is often irrelevant because their main assets (software, patents, brand) are intangible and mostly absent from book value.

Real estate and industrial conglomerates sit in between. P/B can be a useful cross-check, but investors should compare against tangible book value (excluding goodwill from acquisitions) for a cleaner picture.