Understanding the Price-to-Book Ratio

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When you think of the greatest investors in the history of the stock market, names like Warren Buffett and Benjamin Graham come to mind. These legendary investors are proponents of what is known as "value investing," and there is no fundamental analysis metric more associated with value than the price-to-book ratio. While you may never attain Buffett's wealth level, you can become a member of this quiet group that invests in the long game.

Key Takeaways

  • The price-to-book ratio, or "P/B ratio," compares a company's market price to its book value.
  • Analyzing the price-to-book ratio lets you spot stocks for value investing.
  • To calculate the P/B ratio, divide the company's market capitalization by its total book value.
  • The price-to-book ratio can give you some idea of whether you are paying too much, but it's less useful for service companies without a lot of tangible assets.

Defining the Price-to-Book Ratio

Simply put, the price-to-book ratio, or "P/B ratio," is a financial ratio used to compare a company's current market price to its book value. It is also sometimes known as a "market-to-book ratio." 

The idea behind value investing—in the long term—is to find the market sleepers. These are companies that other investors have passed over. Value investors hold on to them as the companies go about their business without gaining any attention from the market. Then, suddenly—without warning or fanfare—a sleeper stock pops up on the screen of some analyst who discovers it and bids up the stock. Meanwhile, as a value investor, you can pocket a hefty profit, sometimes even becoming quite wealthy.

Two Ways to Calculate the P/B Ratio

If you choose to calculate the ratio the first way, the company's market capitalization is divided by the company's total book value from its balance sheet. However, if you choose to calculate the ratio the second way (i.e., using per-share values), you must divide the company's market price per share by its book value per share. In other words, the value is divided by the number of outstanding shares.

Variations by Industry

As with most ratios, there's a fair amount of variation by industry. Industries that require more infrastructure capital (for each dollar of profit) will usually trade at P/B ratios much lower than, for instance, consulting firms. Price-to-book ratios are commonly used to compare banks, because most assets and liabilities of banks are constantly valued at market values. A higher P/B ratio implies that investors expect management to create more value from a given set of assets. It's important to note that P/B ratios do not directly provide any information on the ability of the company to generate profits or cash for shareholders. 

Disadvantages of Using the P/B Ratio

When accounting standards applied by firms vary, P/B ratios may not be comparable, especially for companies from different countries. P/B ratios can be less useful for services and information technology companies with few tangible assets on their balance sheets.

Companies in Distress

The P/B ratio also gives some idea of whether or not an investor is paying too much for what would be left if a company were to go bankrupt immediately. For companies in distress, the book value is usually calculated without the intangible assets that would have no resale value. In such cases, the P/B ratio should be calculated on a "diluted" basis, because stock options may vest upon the sale of the company or the firing of management.

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