The twelve ratios that turn raw financial data into actionable intelligence — valuation, profitability, leverage, and cash flow metrics that drive buy/sell decisions.
1. Calculate and interpret the most important valuation ratios (P/E, P/B, P/S, EV/EBITDA).
2. Use profitability ratios (ROE, ROA, margin analysis) to assess business quality.
3. Evaluate financial risk through leverage ratios (debt/equity, interest coverage).
4. Understand free cash flow yield and dividend payout ratio.
5. Know which ratios matter most for different investment styles.
No single ratio tells the full story. Ratios are most powerful when used in three ways: comparing a company to its industry peers, comparing a company to its own historical values, and combining multiple ratios to build a composite picture. A low P/E means nothing in isolation — but a low P/E combined with high ROE, growing FCF, and insider buying tells a compelling story.
All examples below use TechCorp data from Modules 3.1–3.3, with an assumed stock price of $84.00 and market cap of $42B (500.5M diluted shares × $84).
The P/E ratio tells you how much investors are willing to pay for each dollar of earnings. A P/E of 20.2x means investors pay $20.20 for every $1 of annual profit. Higher P/E suggests the market expects faster growth; lower P/E suggests slower growth or higher risk.
Trailing P/E uses the last 12 months of reported earnings. Forward P/E uses analyst estimates for the next 12 months — generally more useful because stocks are priced on future expectations, not past results.
P/B compares the market price to the company's net asset value (equity). A P/B of 1.0 means you're buying assets at their accounting value. Below 1.0 could signal the stock is undervalued — or that the market doubts the assets are worth what the books say. Asset-heavy industries (banking, manufacturing) trade at lower P/B; asset-light industries (tech, software) trade at much higher P/B because their value is in intangibles not captured on the balance sheet.
P/S is useful when a company doesn't have positive earnings — which is common for high-growth companies reinvesting all revenue into growth. It's also harder to manipulate than P/E because revenue is more straightforward than earnings. A P/S of 3.4x means investors pay $3.39 for every $1 of revenue.
EV/EBITDA is considered the most comprehensive valuation ratio by many professionals because it accounts for debt (through enterprise value) and strips out non-cash charges and capital structure differences (through EBITDA). It's the go-to for comparing companies with different debt levels and tax situations, and it's the standard metric in M&A analysis.
The PEG ratio adjusts the P/E for growth. A stock trading at 30x earnings looks expensive — but if it's growing earnings at 30% per year, the PEG is 1.0, which suggests fair value. The PEG answers: "Am I paying a reasonable price for this company's growth rate?"
Peter Lynch popularized this metric, arguing that a fairly valued growth stock should have a PEG around 1.0. Below 1.0 suggests you're getting growth at a discount; above 2.0 suggests you're overpaying for the growth rate. TechCorp's PEG of 1.35 is reasonable — slightly growth-rich but not extreme.
Limitation: PEG relies on estimated future growth, which is inherently uncertain. A company projected to grow 25% that actually grows 10% has a much higher effective PEG than the initial calculation suggested. Always use conservative growth estimates.
ROE measures how effectively management uses shareholders' capital to generate profit. An 18.1% ROE means TechCorp generates 18 cents of profit for every dollar of equity. This is one of Warren Buffett's favorite metrics — he looks for companies that consistently earn 15%+ ROE without excessive leverage.
Caveat: ROE can be artificially inflated by high debt (which reduces equity in the denominator) or aggressive share buybacks (which reduce equity through treasury stock). Always check the D/E ratio alongside ROE.
ROA measures how efficiently a company uses all of its assets (regardless of how they're financed) to generate profit. Unlike ROE, ROA isn't inflated by leverage. A company with high ROE but low ROA is generating returns primarily through debt, not operational efficiency.
A D/E of 0.37x means TechCorp has 37 cents of debt for every dollar of equity — conservative and comfortable. Companies with D/E above 1.0x have more debt than equity; above 2.0x is aggressive for most industries (though common in banking, utilities, and real estate where assets are stable and predictable).
This tells you how many times over the company can pay its interest bill from operating profits. The higher the better. If this ratio falls below 2.0x, the company is spending more than half its operating income on interest payments — a precarious situation that leaves little room for error.
FCF yield is the cash equivalent of earnings yield — it tells you what percentage of your investment the company generates in free cash flow each year. Think of it as the "real" yield on your equity investment, before management decides how to allocate that cash (buybacks, dividends, debt repayment, or reinvestment).
A 4.64% FCF yield means that for every $100 you invest in TechCorp stock, the company generates $4.64 in free cash flow annually. Compare this to the yield on bonds or savings accounts to assess relative attractiveness.
TechCorp pays out about 20% of its earnings as dividends, retaining the other 80% for growth, buybacks, and other uses. This is a sustainable and conservative payout. A payout ratio above 80% leaves little room for dividend growth or earnings volatility. Above 100% means the company is paying dividends out of reserves or debt — unsustainable.
| Category | Ratio | Value | Assessment |
|---|---|---|---|
| Valuation | P/E (Trailing) | 20.2x | Moderate — in line with market average |
| Valuation | P/B | 3.66x | Tech premium — reasonable for sector |
| Valuation | P/S | 3.39x | Moderate for tech |
| Valuation | EV/EBITDA | 12.9x | Slightly below average — potentially attractive |
| Profitability | ROE | 18.1% | Strong without excessive leverage |
| Profitability | ROA | 10.2% | Healthy asset efficiency |
| Profitability | Operating Margin | 22.0% | Strong pricing power |
| Leverage | D/E | 0.37x | Conservative — ample headroom |
| Leverage | Interest Coverage | 14.7x | Very comfortable |
| Cash Flow | FCF Yield | 4.64% | Fair — attractive vs. bonds |
| Cash Flow | FCF Conversion | 94% | High earnings quality |
| Cash Flow | Dividend Payout | 20.2% | Sustainable, room to grow |
TechCorp looks like a high-quality business at a reasonable valuation: strong margins, efficient capital usage, conservative leverage, and high-quality earnings backed by cash flow. At 20x earnings, you're not getting a bargain, but you're paying a fair price for a company with genuine competitive advantages. This is the kind of analysis that separates informed investors from guessers.
In 2015, several major energy companies were trading at P/E ratios of 5–8x, appearing dramatically undervalued compared to the S&P 500's 18x. Many retail investors bought the "cheap" stocks. But those low P/Es were based on peak earnings from an oil boom that was already ending. As oil prices collapsed, earnings evaporated. Companies that looked like they had P/Es of 5x suddenly had no earnings at all — and their stocks fell 50–70% from already-depressed levels.
The lesson: a low P/E based on peak or cyclical earnings is a trap. Always ask: are these earnings sustainable? What do forward estimates look like? The most important P/E is the one calculated on normalized, sustainable earnings — not last year's peak. This is why we use multiple ratios together rather than making decisions on any single metric.
| Investment Style | Primary Ratios | Why |
|---|---|---|
| Value Investing | P/E, P/B, EV/EBITDA, FCF Yield | Finding undervalued companies relative to their fundamentals |
| Growth Investing | P/S, Revenue Growth, ROE, Gross Margin | Identifying companies with expanding markets and efficient scaling |
| Dividend Investing | Dividend Yield, Payout Ratio, FCF Coverage, D/E | Ensuring dividends are safe, sustainable, and growing |
| Quality Investing | ROE, ROA, FCF Conversion, Operating Margin | Finding businesses with durable competitive advantages |
| Distressed / Turnaround | Current Ratio, D/E, Interest Coverage, P/B | Assessing survival probability and asset-backed value |
Module 4 (Fundamental Analysis) takes these ratios and applies them to real-world investment decisions: building screening criteria, constructing valuation models, and developing investment theses. The ratios are the vocabulary; Module 4 teaches you the grammar.
Every ratio has failure modes. Using a ratio in the wrong context can lead to worse decisions than using no ratio at all.
| Ratio | Fails When... | Alternative |
|---|---|---|
| P/E | Earnings are negative, cyclical, or distorted by one-time items | P/S, EV/EBITDA, or normalize earnings across a cycle |
| P/B | Company is asset-light (software, services) with value in intangibles | P/S or EV/EBITDA for asset-light businesses |
| ROE | Equity is very low or negative (due to buybacks or accumulated losses), inflating ROE | ROA or return on invested capital (ROIC) |
| D/E | Industry norms vary dramatically (banks vs. tech); comparing across sectors is meaningless | Compare only within industry; use interest coverage for cross-sector |
| PEG | Growth estimates are unreliable or the company is mature with low growth | FCF yield for mature companies; P/S for pre-profit growth |
| FCF Yield | Company is in heavy investment phase with temporarily depressed FCF | EV/EBITDA or project normalized FCF after investment cycle |
The golden rule: never make a decision on a single ratio. The TechCorp dashboard approach — using 10–12 ratios across valuation, profitability, leverage, and cash flow — gives you a composite picture that no single metric can provide.
Theory becomes skill through practice. Complete this exercise before moving to Module 4:
Step 1: Choose a company you're interested in. Open their most recent 10-K on SEC EDGAR (Module 2.4 taught you how).
Step 2: Find the three financial statements: income statement (Module 3.1), balance sheet (Module 3.2), cash flow statement (Module 3.3).
Step 3: In a spreadsheet, calculate every ratio from the TechCorp dashboard above using the company's real numbers. You'll need the current stock price and share count (available on any financial site) to calculate valuation ratios.
Step 4: Look up the same company on Finviz or your broker's research page. Compare your calculated ratios to their reported ratios. If there are discrepancies, figure out why — did they use trailing or forward earnings? Did they calculate D/E using total debt or just long-term debt? Understanding these differences makes you a better analyst.
Step 5: Write a one-paragraph assessment: Is this company high-quality (strong margins, good ROE, manageable debt, high FCF conversion)? Is it reasonably valued (P/E, EV/EBITDA, FCF yield relative to its growth rate)? Would you want to research it further?
Every ratio input traces back to a specific statement: net income, revenue, margins, EPS → income statement (Module 3.1). Total assets, equity, debt, book value → balance sheet (Module 3.2). Operating cash flow, CapEx, FCF → cash flow statement (Module 3.3). Stock price, market cap, shares outstanding → market data (your broker or Finviz).
1. A stock trades at $50 with EPS of $2.50. What is the P/E ratio?
2. Why do many professionals prefer EV/EBITDA over P/E for comparing companies?
3. A company has ROE of 25% but D/E of 3.0x. What should you conclude?
4. TechCorp has an FCF yield of 4.64%. What does this mean practically?
5. Energy stocks are trading at P/E of 6x while the S&P 500 is at 18x. Is this definitely a buying opportunity?
You can now read all three financial statements and calculate the key ratios that drive investment decisions. Module 4 applies this knowledge to real-world fundamental analysis — macro indicators, valuation models, and building investment theses.