Two retail stocks cost $20 and $50 a share. Lin thinks the first is cheaper. Then she discovers annual earnings per share of $2 and $2.50. Debt changes the comparison again. Which price is buying more of the business's economic results?
A share price starts the question. Valuation asks what earnings, assets, or operating results that price represents, and whether those results can persist. Aligning the numerator and denominator reveals what the comparison actually measures before you decide what it means.
What you will be able to do
- Recalculate P/E and simplified EV/EBITDA and explain why their rankings can differ.
- Separate fiscal-year, trailing-twelve-month, and forecast inputs, recognizing losses and cyclical peaks that undermine ordinary comparisons.
- Save a multiples record with sources, reasons for comparability, conditional ranges, and unresolved conclusions.
A quoted price and an estimated value answer different questions
Price is a market quotation. Intrinsic value is an estimate based on fundamentals, future results, and risk, rather than an answer copied from a statement. CFA Institute emphasizes judgment in selecting models and inputs, including limitations imposed by the available information.[1]
A multiple divides price or market value by a scale such as earnings, book equity, or sales. Think of comparing differently sized packages using a common unit. The analogy stops short of treating businesses like identical bags of rice: their future growth, risk, and cash requirements differ.
Relative valuation asks how the market prices comparable results. Its usefulness depends on both comparability and the chosen standardization, as Damodaran explains.[2] If every peer reflects excessive optimism, averaging their multiples does not remove that optimism. A lower figure can prompt an investigation without establishing an independently correct value.
Put $20 and $50 on a common scale
Retailers A and B are independent fictional businesses, not renamed Costco or Target data. Use one valuation date, U.S. dollars, and earnings attributable to common shareholders for the same full year. Each company has one common-share class, no other dilutive instruments, and an unchanged share count throughout the year. All figures are teaching inputs, not quotations or forecasts.
A has 100 million shares at $20, giving common-equity market value of $2 billion. Its $200 million in annual earnings attributable to common shareholders gives earnings per share of $2. B has 10 million shares at $50, equity market value of $500 million, and corresponding earnings of $25 million, or $2.50 a share.
Price-to-earnings, or P/E, divides share price by matching earnings per share. A's $20 divided by $2 is 10 times; B's $50 divided by $2.50 is 20 times. Equity market value divided by the corresponding total earnings produces the same results.[3]
Read A's 10 times as the market paying $10 of common-equity price for each $1 of the stated year's earnings. It is not a ten-year payback guarantee. The company may retain earnings, reinvest, or repay debt, and future profits may change.
For now, the supported conclusion is that A has the lower P/E. Perhaps it grows more slowly, faces greater risk, or has unusually strong current earnings. B's higher figure may reflect more optimistic expectations. The ratios identify a difference to explain; they do not assign investment-quality scores.
Notice why quoting both the per-share and total calculation helps. The $50 share is not fifty dollars of an otherwise identical package. Its share count and earnings claim differ. The total-value calculation checks that your per-share numerator and earnings denominator refer to the same ownership interest.
Debt can reverse the ranking
P/E concerns the price of common equity and earnings attributable to it. To compare operating businesses across financing structures, add another layer. At the same valuation date, give A debt with a market value of $900 million and $100 million of cash eligible for the stated adjustment. B has no debt and $100 million of adjustable cash.
Here, enterprise value, or EV, is simplified to common-equity market value plus debt market value minus that cash. Assume no preferred stock, noncontrolling interests, leases, or other EV adjustments. These are explicit omissions in a teaching case, not items to assume away in real research.[3]
A's EV is $2 billion plus $900 million minus $100 million: $2.8 billion. B's is $500 million minus $100 million: $400 million. Their same-year EBITDA is given as $300 million and $60 million, respectively, using one consistent definition without further adjustments.
EBITDA means earnings before interest, income taxes, depreciation, and amortization. Dividing EV by those earnings gives approximately 9.33 times for A and 6.67 times for B. B now has the lower multiple, whereas A had the lower P/E.
That reversal does not show that one calculation failed. A's business has debt claims alongside its common equity; B's EV includes the specified cash subtraction. The measures relate different capital claims to different earnings levels. Combining the rankings into a single universal cheapness league would hide that distinction.
Match the numerator's claim to the denominator's results. Common-equity value belongs with corresponding common-shareholder earnings. EV belongs with an appropriate enterprise-level operating measure. Dividing EV by shareholder net income and comparing the answer with another firm's P/E mixes the two levels: shareholder earnings already reflect interest, while EV includes debt claims.
EBITDA also is not cash you can simply withdraw. It does not fully reflect capital expenditure, working-capital changes, taxes, and other funding demands. A business requiring continuing equipment investment may look more productive than it really is if those costs disappear from the comparison. Lease treatment and accounting adjustments can also disturb comparability.
Use other multiples to locate the missing question
You do not need four complete models today. Use the following map to decide what to investigate when a measure appears.
| Measure | What is being compared? | First gap to check |
|---|---|---|
| P/E | Common-equity price versus attributable earnings | Positive earnings, unusual items, basic or diluted basis |
| Price-to-book | Common-equity value versus corresponding book equity | Positive equity, asset quality, treatment of intangible investment |
| Price-to-sales | Equity value versus revenue | Margins, financing, and cash needs |
| EV multiples | Enterprise value versus matching operating results | Debt, cash, other claims, denominator definitions, investment needs |
Book equity is an accounting residual associated with the relevant shareholders. It is not automatically the cash recoverable in immediate liquidation. Price-to-sales may avoid some of net income's negative-denominator problems, yet put low-margin, cash-intensive operations beside high-margin firms without explaining the difference.
Names such as “adjusted EBITDA” deserve particular attention. Two companies may remove different expenses while using the same label. Obtain each reconciliation before treating the denominators as comparable. Changing one key definition can invalidate an otherwise tidy ranking.
Keep the earnings calendar attached
A historical P/E can use the latest completed fiscal year's earnings. TTM, or trailing twelve months, may combine annual and more recent interim information. A forward P/E uses earnings that have not yet occurred. Keep them in separate, dated fields rather than retaining one unlabeled P/E.
In a separate synthetic example, last fiscal year's earnings were $100 million. The latest disclosed quarter earned $30 million; the matching quarter a year earlier earned $20 million. If periods, accounting, and business scope align, TTM earnings are $100 million plus $30 million minus $20 million, or $110 million.
Adding the new quarter alone would produce $130 million and count the old corresponding quarter again. The subtraction replaces that quarter; it does not discard an inconvenient result. Cumulative half-year reports, changed fiscal years, or acquisitions require fresh checks before applying this simple bridge. Historical research also needs information that was publicly available at the research date.
For forecasts, identify the estimator, reasoning, and update date. Suppose A's next-year profit falls from $200 million to $100 million while price and share count stay fixed. Under that scenario, its P/E becomes 20 rather than 10. A low historical multiple can reflect a cyclical earnings peak instead of undervaluation.
Let a denominator make the comparison unavailable
At zero earnings, ordinary P/E is undefined. Negative earnings can produce an arithmetic negative ratio, but that result does not join the usual “lower positive P/E is cheaper” ordering. Negative book equity similarly undermines an ordinary positive price-to-book comparison.
Very small positive earnings can produce an unusually high multiple. Investigate one-time items and cyclicality before interpreting it. Replacing an awkward denominator with your preferred “normal earnings” can hide a judgment inside an apparently objective metric. Preserve the reported value, the adjustment, its reason, and supporting material.
An unavailable comparison is useful information. It identifies a limitation of this measure for this business and period. Filling every cell is less valuable than keeping the boundary visible so a later reader does not mistake an unsupported ranking for a conclusion.
Put conditions beside the valuation range
Return to fictional B for a sensitivity exercise. Give it two possible sustainable annual earnings levels, $25 million and $35 million. Also assume a research comparison range of 12 to 16 times earnings, with 10 million shares unchanged. These are teaching assumptions, not estimates derived from an actual peer dataset.
At $25 million, the assumed multiples give equity values of $300 million to $400 million, or $30 to $40 a share. At $35 million, they produce $420 million to $560 million, or $42 to $56 a share. Across both scenarios, the illustrated range is $30 to $56.
That span is neither a statistical confidence interval nor a boundary on future trading prices. It makes two research questions explicit: what supports sustainable earnings, and why does the chosen comparison multiple apply? Without answers, the midpoint is not an evidence-based target price. A wide range cannot compensate for unsupported inputs.
Find a real denominator without inventing a price
The C1-R retrospective materials include Costco's Form 10-K for the fiscal year ended August 31, 2025. Its consolidated income statement on printed page 37 reports diluted net income per common share of $18.21.[4] This is a fixed historical source-location exercise, not the latest earnings figure and not material available at C1's original frozen observation dates.
A historical P/E still needs a verified price for a selected valuation date, confirmation that the report was public then, and compatible share units. Label the denominator as full-fiscal-year diluted earnings. No matching price is supplied here, so we do not calculate a “current Costco P/E” or transfer A and B's fictional multiples to Costco.
Explain, diagnose, and then change the inputs
First explain why A's lower P/E does not establish a cheaper investment. Then diagnose an analyst who divides A's $2.8 billion EV by $200 million net income, gets 14 times, and puts it in a P/E comparison. Write your answers before checking the discussion.
The first answer should address earnings persistence, growth, risk, and accounting, alongside the fact that low share price alone determines neither the multiple nor attractiveness. The analyst has mixed enterprise and equity measures. P/E uses $2 billion divided by $200 million: 10 times. The specified EV/EBITDA is about 9.33 times.
Now use independent fictional C. At one valuation date, it has $900 million of common-equity market value, $300 million debt market value, $100 million adjustable cash, and no other EV adjustments. TTM attributable earnings are $45 million; consistently defined EBITDA is $100 million. Calculate both multiples. If forecast earnings become a $30 million loss, is a forward P/E of negative 30 “cheaper than 20”?
Reference answers · reveal
Answer guide: TTM P/E is 20. EV is $1.1 billion, so EV/EBITDA is 11. Negative forecast earnings permit arithmetic division but not the ordinary positive-P/E ranking. Record the forecast loss and the comparison's inapplicability, then investigate other methods only where evidence supports them.
Save a multiples checking card
Use A and B or a real research subject. Record valuation date, equity or enterprise basis, price and share-count sources, debt and cash adjustments, other claims, denominator definition and period, forecasts or adjustments, and information availability. Missing prices or adjustments stay unresolved.
List comparables and reasons, differences, and treatment of unusual denominators. Add an evidenced scenario and preserve the first version. Cover the output multiples for a self-check: do numerator and denominator belong to consistent capital claims, currency, and periods? If not, fix the definitions before adding decimal places.
Match the measure before interpreting the difference
Ask which claim is being priced, what result is underneath it, and when that result occurred. Identical labels do not establish identical definitions. Zero, negative, or unusual denominators trigger investigation rather than a forced cheapness ranking.
Then examine growth, risk, cash requirements, and expectations. Multiples provide research leads; valuation remains conditional judgment. Keeping assumptions and gaps beside the range tells you which input new evidence should change.
References
- CFA Institute: Equity Valuation—Concepts and Basic Tools, 2026 public introduction and summary. No paid curriculum reviewed.
- Aswath Damodaran: An Introduction to Valuation. Relative valuation, comparables, and standardized prices.
- CFA Institute: Market-Based Valuation—Price and Enterprise Value Multiples, public summary. Definitions and matching capital claims; no paid course reviewed.
- Costco 2025 Form 10-K, consolidated income statement, printed page 37. C1-R retrospective source only.
Sources inspected October 30, 2026. AI-assisted draft; independent AI full-text and bilingual review is complete; human financial review and target-reader testing remain pending. Fictional retailers and ranges are original synthetic teaching inputs.