All three are price multiples, but they divide by different fundamentals. P/E divides by net earnings, so it captures profitability but breaks down for loss-makers and varies with one-off items. P/S divides by revenue, which is harder to manipulate but ignores margins and capital intensity. P/B divides by book equity — a balance-sheet measure that is far more stable than earnings and that works even for unprofitable companies, but only when assets and liabilities are reported close to fair value. Most analysts triangulate with all three rather than relying on one.

A P/B under 1.0x means the market values the company below its accounting equity. It is common for banks during credit cycles (2008-2009 large U.S. banks, 2023 regional banks after Silicon Valley Bank), for real estate companies when property values are falling, and for industrial firms with impaired assets. Sometimes it is a genuine value opportunity, but often the market is pricing in coming write-downs that have not hit the books yet. Always check tangible book, non-performing loans or asset impairments, and management commentary before assuming sub-1x P/B equals undervalued.

Under U.S. GAAP, internally developed intangible assets — software code, patents created in-house, brand value, customer relationships, network effects — are mostly expensed as incurred rather than capitalized. A SaaS company that spends a decade building a moat has very little of that value on its balance sheet. The stock price reflects the economic value, but the book value does not, so the ratio of the two looks extreme. P/B above 10x is normal for software leaders; the metric is simply uninformative there.

Intangibles cut two ways. Acquired intangibles like goodwill sit on the buyer's balance sheet at the price paid and inflate book equity, making P/B look lower than the underlying tangible business deserves. Internally generated intangibles never appear at all, making P/B look artificially high for organic builders. The standard fix is to run price-to-tangible-book (P/TBV) for acquisitive firms and to deemphasize P/B entirely for asset-light businesses. Banking analysts almost always quote P/TBV rather than P/B.

From Damodaran's industry data archive at NYU Stern (U.S. universe, updated annually): regional and money-center banks typically trade between 0.8x and 1.5x; insurance carriers 1.0x to 2.0x; utilities 1.2x to 2.0x; integrated oils 1.5x to 2.5x; industrials and consumer cyclicals 2.0x to 4.0x; consumer staples and healthcare 3.0x to 6.0x; software and semiconductors often 5.0x to 15.0x or higher. Always benchmark a P/B reading against its own sector median, not against the broader market average.

Yes, they are algebraically identical. P/B = Stock Price / BVPS, and market-to-book = Market Capitalization / Total Common Equity. Since market cap is price times shares and total equity is BVPS times shares, the share count cancels and both expressions equal the same multiple. Use the per-share form when you only have a stock price and a per-share book value, and use the whole-company form when working with market cap and total equity from a screener.

Benjamin Graham used a P/B threshold (often below 1.5x, combined with a P/E below 15) as one filter in his classic defensive-investor screen. Fama and French built P/B (or its reciprocal, book-to-market) into the seminal three-factor model, where high book-to-market stocks earned a long-run premium known as the value factor. Modern value investors use P/B as a starting screen, especially in financials and other asset-heavy sectors, then layer ROE, debt levels, and earnings quality on top to separate genuine value from value traps.