Investing: Valuation Ratios

Valuation ratios help investors assess whether a stock is overvalued, undervalued, or fairly priced by comparing its market price to a financial metric — such as earnings, book value, or revenue.

No single ratio tells the full story. Each ratio captures a different aspect of a company's value, and each works best within a specific industry or business model context.

• Always compare ratios against industry averages and direct competitors — a P/E of 30 may be cheap for a fast-growing tech company but expensive for a utility.
• Ratios can be distorted by accounting choices, one-time charges, or unusual earnings periods. Use with caution.
• Combine valuation ratios with qualitative analysis — management quality, competitive moat, and growth runway all matter beyond the numbers.

Ratio	Formula	What It Shows
P/E Ratio	Stock Price ÷ EPS	How much investors pay per $1 of earnings
Forward P/E	Stock Price ÷ Estimated Future EPS	Valuation based on expected future earnings
P/B Ratio	Stock Price ÷ Book Value Per Share	Market value vs. net asset value
P/S Ratio	Market Cap ÷ Total Revenue	Valuation relative to revenue — useful for unprofitable companies
EV/EBITDA	Enterprise Value ÷ EBITDA	Business value relative to operating cash flow
Dividend Yield	Annual Dividend ÷ Stock Price	Income return as a percentage of price
Earnings Yield	EPS ÷ Stock Price	Inverse of P/E — useful for comparing to bond yields
PEG Ratio	P/E ÷ Earnings Growth Rate	P/E adjusted for growth — a PEG below 1.0 may signal undervaluation

P/E Ratio (Price-to-Earnings): The most widely used valuation metric. The S&P 500 historical average P/E is roughly 15–20x. A high P/E may reflect growth expectations; a low P/E may signal undervaluation or declining business prospects. Use trailing P/E (based on past earnings) and forward P/E (based on estimates) together.

P/B Ratio (Price-to-Book): Compares a stock's market price to its book value (assets minus liabilities). A P/B below 1.0 may indicate undervaluation — the stock trades below the company's net asset value. Value investors like Warren Buffett historically favored low P/B stocks.

EV/EBITDA (Enterprise Value to EBITDA): A capital-structure-neutral ratio that compares the total value of the business (equity + debt − cash) to its operating earnings before interest, taxes, depreciation, and amortization. A typical range is 6–12x for most industries. Particularly useful for comparing companies with different debt levels.

PEG Ratio (Price/Earnings to Growth): Adjusts the P/E ratio by the company's earnings growth rate. A PEG of 1.0 suggests fair value; below 1.0 may indicate undervaluation relative to growth potential. Developed by investor Peter Lynch as a more balanced alternative to P/E alone.

Scenario	Best Ratio to Use
Comparing profitable mature companies	P/E or Forward P/E
Evaluating asset-heavy businesses (banks, real estate)	P/B Ratio
Analyzing companies with negative earnings	P/S Ratio
Comparing companies with different debt levels	EV/EBITDA
Assessing income-focused dividend stocks	Dividend Yield
Comparing growth stocks to their growth rate	PEG Ratio
Comparing stocks to bonds for relative value	Earnings Yield

• Cyclical industries (energy, commodities): P/E can be misleading at earnings peaks — use EV/EBITDA or P/S instead.
• Financial sector (banks, insurers): P/B is most relevant because assets and liabilities dominate their balance sheets.
• Early-stage or unprofitable companies: P/S or EV/Revenue ratios work when there are no earnings to measure.

• Morningstar: Provides detailed ratio analysis, historical P/E charts, and industry comparisons for thousands of stocks and funds.
• Finviz Stock Screener: Filter stocks by P/E, P/B, P/S, dividend yield, and other metrics — free with real-time data options.
• Macrotrends.net: Historical valuation data for individual stocks and major indices, including S&P 500 P/E going back decades.
• Simply Wall St: Visual valuation reports combining multiple ratios into a clear, accessible analysis for individual investors.
• SEC EDGAR: Access a company's 10-K and 10-Q filings directly to pull raw financial data for ratio calculations.