To evaluate individual securities and portfolios, investors rely on a range of fundamental and statistical measures. The price-to-earnings (P/E) ratio compares a stock's price to its earnings per share, offering a quick indication of valuation. A low P/E may suggest undervaluation, while a high P/E often reflects expectations of strong future growth, and comparisons are most meaningful within the same industry. Earnings per share (EPS) itself is calculated by dividing a company's net profit by its outstanding shares, with trailing EPS using historical data and forward EPS reflecting analyst estimates.
Beyond earnings, profitability and leverage metrics help assess a company's financial health. Return on equity (ROE) measures how efficiently a company generates profit from shareholders' equity, calculated as net income divided by equity. An ROE above 15 percent is generally considered strong, though comparisons should be made against peers. The debt-to-equity (D/E) ratio indicates financial leverage by dividing total debt by shareholders' equity; a lower ratio suggests greater stability, while a higher ratio signals greater risk, with appropriate levels varying widely by industry.
At the portfolio level, several metrics capture risk and performance. Beta measures a stock's volatility relative to the overall market, where a beta of 1 matches the market, a beta above 1 indicates greater volatility, and a beta below 1 indicates a more defensive profile. Alpha measures a portfolio's excess return over its benchmark after adjusting for risk, with positive alpha indicating outperformance attributable to skill. The Sharpe ratio evaluates risk-adjusted return by subtracting the risk-free rate from the portfolio's return and dividing by its standard deviation, rewarding higher returns per unit of risk, with values above 1 generally considered good. Standard deviation itself quantifies an investment's price volatility, with higher values indicating greater risk and roughly 68 percent of returns expected to fall within one standard deviation of the average. Underlying all these metrics are two broad analytical approaches: fundamental analysis, which evaluates securities using economic, financial, and qualitative factors to estimate intrinsic value, and technical analysis, which studies price charts, patterns, and trading volume to forecast short-term price movements on the assumption that history tends to repeat.