Price-to-Earnings (P/E) Ratio

Trailing P/E uses the last twelve months (LTM) of actual EPS. Forward P/E uses consensus analyst estimates for the next twelve months (NTM). Forward P/E is more commonly used by institutional investors because markets price in future expectations. A company with a trailing P/E of 25x and forward P/E of 20x is expected to grow earnings by 25% over the next year. When discussing P/E, always specify which EPS figure you're using.

A higher P/E suggests investors expect higher future growth or are willing to pay a premium for quality. The S&P 500's historical average P/E is about 15–17x. Growth stocks (tech, SaaS) often trade at 25–40x+ forward P/E. Value stocks (utilities, banks) trade at 8–15x. A 'low' P/E can signal a cheap stock — or a company with deteriorating fundamentals. Always pair P/E analysis with growth rate analysis (PEG ratio = P/E / EPS growth rate). A PEG below 1.0 suggests the stock may be undervalued relative to its growth.

P/E is an equity-level multiple (share price to EPS, both equity measures), while EV/EBITDA is an enterprise-level multiple. P/E is distorted by capital structure (interest expense affects EPS), tax rate differences, and non-cash charges. EV/EBITDA avoids these distortions. However, P/E is the standard multiple for financial institutions (banks, insurance) because their revenue comes from managing liabilities, making EBITDA less meaningful. P/E is also used in comparable company analysis for consumer-facing companies where investors think in terms of share price.

P/E is meaningless for companies with negative earnings. Earnings can be manipulated through accounting choices more easily than EBITDA. P/E ignores the balance sheet — a company with massive debt may have a low P/E but be risky. Non-recurring items can distort trailing P/E. For cross-border comparisons, different tax rates make P/E less comparable than EV/EBITDA. Despite these limitations, P/E remains the most quoted valuation metric because of its simplicity and long history.