Equity is a very important concept for investors. For instance, in looking at a company, an investor might use shareholders’ equity as a benchmark for determining whether a particular purchase price is expensive. If that company has historically traded at a price to book value of 1.5, for instance, then an investor might think twice before paying more than that valuation unless they feel the company’s prospects have fundamentally improved. On the other hand, an investor might feel comfortable buying shares in a relatively weak business as long as the price they pay is sufficiently low relative to its equity.