P/B ratio explained: price-to-book in fundamental analysis

The P/B ratio (Price-to-Book) compares a stock's market price to the company's book value per share — its net assets as recorded on the balance sheet. It's especially useful for asset-heavy companies: banks, insurers, and industrials. But misreading it can be costly: a low P/B is not always a bargain.

• P/B = Stock Price / Book Value Per Share — compares market price to net accounting worth
• P/B < 1 may be opportunity or value trap: always check asset quality and ROE
• Always compare P/B within the same sector — ranges vary enormously
• High P/B in tech and branded consumer is normal — intangibles aren't in the book value
• Combine P/B with ROE: high ROE + low P/B is the best signal; low ROE + high P/B is a red flag
• Benchmarks: banks 0.5–1.5×, industrials 1–3×, tech brands 5×+

How to calculate P/B

P/B = Stock Price / Book Value Per Share. Book Value Per Share = (Total Assets − Total Liabilities) / Shares Outstanding. Example: a company with €500M in assets, €300M in liabilities, and 50M shares has a book value of (500−300)/50 = €4 per share. If the stock trades at €6, P/B = 1.5. Book value represents what shareholders would theoretically receive if the company liquidated all its assets and paid all its debts.

How to interpret P/B by range

P/B < 1 means the market values the company below its accounting net worth — it trades below liquidation value. This can signal a genuine opportunity (undervalued company) or serious problems (the market doesn't trust the quality of those assets, or expects future losses). P/B 1–3 is reasonable for most traditional industries. P/B > 5–10 is common in technology and strong consumer brands, where the real value is in intangibles (brand, software, data, user base) that don't appear on the balance sheet.

P/B by sector: the benchmarks that actually matter

P/B only makes sense compared within the same sector. Reference ranges: Banks and insurers typically trade at 0.5–1.5× in normal conditions. Industrials and energy companies usually 1–3×. Consumer staples with strong brands (Nestlé, L'Oréal, Procter & Gamble) 3–8×. Large-cap tech (Apple, Microsoft, Alphabet) often 5–20× or more — because intangibles dominate their value. Comparing a bank's P/B to a software company's is meaningless.

The value trap: when low P/B is a warning, not an opportunity

A very low P/B can look like a bargain but be a trap. Warning signs: ROE is consistently low or negative (the company generates poor returns on its assets), earnings are declining year over year, the sector faces structural decline (think print media or legacy retail), or the balance sheet contains assets recorded at above-market values — such as overvalued real estate, doubtful receivables, or obsolete inventory. If book value is inflated, the true P/B is higher than reported.

Where P/B fails

P/B is unreliable for service companies (minimal tangible assets), tech companies (their value is in intangibles that accounting standards don't fully capture), companies with negative book value (high leverage or accumulated losses), and businesses where intellectual property is the main asset. In these cases, P/E ratio, EV/EBITDA, or Price-to-Sales are more meaningful alternatives.

P/B + ROE: the most powerful combination

The P/B + ROE combination is more informative than either ratio alone. High ROE + high P/B: the market is paying a premium because the company generates excellent returns on capital — this can be justified. Low ROE + high P/B: the premium is hard to justify — overvalued or deteriorating business. High ROE + low P/B (under 1): a genuinely undervalued situation — rare but powerful. Low ROE + low P/B: typically reflects structural problems, not an opportunity. This framework, sometimes called the Joel Greenblatt approach, is one of the most reliable screens in value investing.

Frequently asked questions

What does a P/B below 1 mean?

The market values the company below its book equity. It may be an opportunity or a sign the assets are worth less than the books say.

Where is P/B most useful?

In asset-heavy sectors such as banks, insurers and industrials. It says little about software or brand-driven companies.

How do P/B and ROE relate?

A high ROE justifies a high P/B. A low P/B with a high, stable ROE can signal undervaluation.

Where do I find book value?

On the balance sheet: shareholders' equity divided by the number of shares.

Read further

• The Intelligent Investor (Benjamin Graham). It gives you: The origin of the margin of safety and of using the market rather than following it.