Book Value

How it's calculated

Book Value = Total Assets − Total Liabilities

It's the same number as shareholders' equity on the balance sheet — the residual claim on the company after every creditor has been paid in full. Per share, it's just book value divided by shares outstanding.

For a hypothetical company with $10B of assets, $6B of liabilities, and 100 million shares outstanding, book value per share is ($10B − $6B) / 100M = $40 per share. If the stock trades at $200, the market is paying 5× book.

Price-to-book ratio

The price-to-book (P/B) ratio is the cousin of the P/E ratio:

P/B = Market Price per Share / Book Value per Share

A P/B of 1.0 means the market is valuing the company at exactly the accounting net worth. Below 1 means the market believes the company is worth less than its books suggest; above 1 means the market believes the company has unrecorded value (brand, technology, future growth, etc.).

Historically, value investors — Benjamin Graham most famously — used low P/B as a screen for undervalued stocks. A diversified basket of low-P/B stocks ("the value factor") outperformed the market over much of the 20th century.

Why book value matters less for modern companies

Two structural shifts have reduced book value's usefulness as a valuation anchor:

• Intangibles dominate. Apple's brand, Microsoft's customer relationships, Google's data, and Visa's network effect aren't on their balance sheets in any meaningful way. Internally developed intangibles can't be capitalized under standard accounting; only acquired ones can (as goodwill). The result: high-quality modern companies often trade at 10–20× book value not because they're overpriced but because their book value misses most of what makes them valuable.
• Share buybacks reduce book value. When a company spends cash to buy back stock, both cash (asset) and shareholders' equity decrease. Apple has bought back over $700B of stock in the last decade, mechanically lowering its book value while the underlying business has grown enormously.

The "value premium" — historical outperformance of low-P/B stocks — has been weak to nonexistent for most of the 21st century, partly because of these dynamics.

Where book value still matters

Book value remains meaningful in specific industries:

• Banks — assets are mostly financial (loans, securities) that are reasonably well-marked. Bank stocks are commonly compared on P/B; well-run banks tend to trade above 1.0×, troubled ones below.
• Insurance companies — similar logic; balance sheet is mostly investible securities.
• Real estate — though "tangible book value" or NAV (net asset value) is often used instead of accounting book.
• Asset managers — though here it's the assets under management, not the book itself, that drive value.

For tech, consumer brands, software, and pharma, P/B is essentially uninformative.

Tangible book value

To strip out goodwill and other intangibles (which can be impaired or written off), some analysts use tangible book value = total assets − goodwill − intangibles − total liabilities. This gives a more conservative liquidation-style estimate, useful when evaluating banks or distressed situations. Tangible book per share is what acquirers pay attention to in distressed M&A.