Using three core ratios together—P/E, debt-to-equity, and ROE—provides an individual investor with a simple yet powerful framework for screening stocks before conducting deeper research. Each ratio shines a light on a different question: “What price am I paying?” (P/E), “How is the company financed?” (debt-to-equity), and “How effectively is management using shareholder money?” (ROE). None of them should be used in isolation, but together they can help narrow the vast universe of stocks into a manageable watchlist that fits an investor’s goals and risk tolerance.
The price-to-earnings (P/E) ratio compares the current share price to earnings per share and tells you how many dollars investors are paying for one dollar of earnings. A higher P/E often means the market expects stronger growth, while a low P/E may signal a bargain or real problems—context matters. A practical way to use P/E is to compare a company’s multiple to its own history and to close peers in the same industry; a stock trading at a lower P/E than similar businesses, with no obvious red flags in its fundamentals, might be worth a closer look.
Debt-to-equity (D/E) looks at how much of the company’s capital structure is funded by borrowing versus shareholder equity, giving you a quick read on financial leverage. A high D/E ratio means the company leans heavily on debt, which can boost returns in good times but amplifies risk if cash flows fall or interest rates rise. A very low D/E can indicate a conservative balance sheet and greater resilience during downturns. Still, it might also suggest that management is passing on growth opportunities that could reasonably be funded with some leverage. When comparing debt levels, it is important to stay within industries—utilities and telecoms often run higher leverage than software or healthcare, for example.
Return on equity (ROE) measures how efficiently a company converts shareholder equity into profits by dividing net income by average equity. Investors generally prefer businesses with consistently higher ROE, because that indicates the company is good at turning invested capital into earnings and potentially compounding value over time. However, ROE can be artificially inflated if a firm takes on significant debt, since greater leverage shrinks the equity base; this is why ROE should always be interpreted alongside the debt-to-equity ratio. Looking at trends is helpful: a stable or rising ROE over several years, without a big run-up in debt, is often a positive sign of durable competitive advantages and disciplined management.
One way an investor can put these three ratios to work is as a simple, layered screen. First, use P/E to filter out obvious extremes: avoid stocks with valuations far above their industry unless there is a clear, well-supported growth story, and flag those with unusually low P/E for further investigation. Second, check debt-to-equity to avoid companies whose leverage appears excessive for their sector or whose debt has been rising much faster than equity, especially in cyclical industries. Third, focus on names that combine reasonable valuation with consistently solid ROE and manageable leverage, recognizing that different industries will have different “normal” ranges for each metric.
For a practical workflow, many investors build a simple spreadsheet or use a stock screener to pull P/E, D/E, and ROE for a short list of companies in a given sector, then sort and compare them. Instead of hunting for a single “perfect” ratio, they look for alignment: valuation that is not stretched, leverage that is appropriate to the business model, and returns on equity that suggest capable management and a durable franchise. From there, the numbers are a starting point—not the finish line—for deeper fundamental work, including reading annual reports, understanding the competitive landscape, and assessing the quality of management and earnings.
If you were explaining this framework to your own clients, would you want concrete numerical examples in the blog (e.g., comparing two hypothetical companies side by side), or keep it at this concept level?
Sources:
Investopedia, “Price-to-Earnings (P/E) Ratio” – https://www.investopedia.com/terms/p/price-earningsratio.asp
Charles Schwab, “Five Key Financial Ratios for Stock Analysis” – https://www.schwab.com/learn/story/five-key-financial-ratios-stock-analysis
Intrinio, “5 Most Common Financial Ratios for Analyzing Stocks” – https://intrinio.com/blog/5-most-common-financial-ratios-for-analyzing-stocks
LTSI, “Key Financial Ratios: P/E, P/B, ROE, ROA” – https://ltsi.substack.com/p/key-financial-ratios-pe-pb-roe-roa
HeyGoTrade, “10 Financial Ratios Every Stock Investor Should Know” – https://www.heygotrade.com/en/blog/financial-ratios-stock-investors-guide/
