Scenario Analysis: Base, Bull and Bear

By Ryan O'Connell, CFA, FRM Published October 20, 2026
Table of Contents

    A stock priced at $20 can look attractive or expensive depending on what you assume about its future. Scenario analysis makes those assumptions visible. Instead of relying on one price target, you build several business stories and calculate what each would imply for earnings and valuation.

    This guide follows one hypothetical company from revenue to net profit margin, earnings per share, and an implied share price. Its base, bull, and bear cases produce $22, $36, and $10.80 respectively. Understanding the assumptions behind those figures is more useful than treating any one of them as a prediction.

    What Is Scenario Analysis?

    Scenario analysis evaluates how an investment or business would perform under different sets of assumptions. In stock analysis, each case connects an operating forecast with a valuation assumption.[1]

    Key Concept

    A useful scenario tells a coherent story, reconciles mathematically, and identifies assumptions you can later compare with evidence. A precise price target cannot compensate for an implausible business forecast.

    For this article, the three labels mean:

    Base, bull, and bear cases in a business valuation
    Case Purpose Business story
    Base A central reference point A reasonable operating path against which to compare alternatives.
    Bull A favorable, plausible alternative Stronger business performance and a valuation consistent with that outlook.
    Bear An adverse, plausible alternative Weaker performance and a valuation consistent with the risks.

    These labels do not assign probabilities. They also do not establish the best or worst outcome that could ever occur. Keep the same forecast horizon and valuation method across cases so the results can be compared.

    Watch: Scenario Analysis Explained: Base, Bull and Bear

    From Business Assumptions to Share Price

    The example uses a simple earnings-based valuation chain. Revenue is sales. Net profit margin is the percentage of revenue remaining after expenses, including interest and taxes. It differs from gross and operating profit margins.[2]

    Revenue to Net Income
    Net income1 = Revenue1 × Net margin1
    The subscript 1 identifies the forecast year. Express the margin as a decimal when calculating.

    Assume all modeled net income is available to common shareholders. Divide it by the share count to calculate earnings per share (EPS):

    Net Income to EPS
    EPS1 = Net income1 / Shares1
    Shares means the average common share count for the forecast year; it remains constant in this example.

    The P/E ratio equals price divided by EPS. Rearranging that relationship gives an implied price when you supply an earnings estimate and a matching multiple.[2]

    EPS to Implied Future Price
    Price1 = EPS1 × Assumed P/E1
    The multiple is an assumption about how investors will value those earnings at the forecast date.

    Match the dates: here, the price one year from now uses earnings for that forecast year and an assumed year-end P/E on those earnings. A forward P/E at that future date would instead use the following year’s expected EPS.[3]

    For a real company, check the EPS denominator. Microsoft’s annual report, for example, distinguishes weighted-average basic shares from shares adjusted for dilutive potential common stock.[4] A fixed share count is a simplifying assumption, not something every forecast should inherit.

    Scenario Analysis Example: Three Valuations

    One Hypothetical Company, One-Year Horizon

    Suppose a company currently has $100 million in annual revenue, 10 million common shares, and a $20 share price. Estimate its price one year ahead. Shares remain at 10 million throughout the forecast year, all net income belongs to common shareholders, and the three cases use the same method.

    All figures below are hypothetical. Price returns exclude dividends, fees, and investor taxes.

    Hypothetical base, bull, and bear assumptions and results for the same forecast year
    Measure Base Bull Bear
    Revenue ($ millions) 110 125 90
    Revenue growth from $100 million 10% 25% −10%
    Net profit margin 10% 12% 8%
    Net income ($ millions) 11 15 7.2
    Common shares (millions) 10 10 10
    EPS $1.10 $1.50 $0.72
    Assumed year-end P/E 20× 24× 15×
    Implied year-end price $22.00 $36.00 $10.80
    One-year price return from $20 +10% +80% −46%

    Base Case: $22

    Suppose demand remains healthy without an exceptional improvement. Revenue grows 10% to $110 million, net margin is 10%, and investors pay 20 times the forecast year’s earnings at year-end.

    Net income: $110 million × 0.10 = $11 million.
    EPS: $11 million / 10 million shares = $1.10.
    Implied price: $1.10 × 20 = $22.
    Price return: ($22 − $20) / $20 = 10%.

    Bull Case: $36

    Suppose stronger demand and better execution lift revenue 25% to $125 million. Spreading fixed costs over more sales helps support an assumed 12% net margin. Investors pay 24 times earnings because they expect stronger growth to continue beyond the forecast year. Those are assumptions to defend, not automatic consequences of higher sales.

    Net income: $125 million × 0.12 = $15 million.
    EPS: $15 million / 10 million shares = $1.50.
    Implied price: $1.50 × 24 = $36.
    Price return: ($36 − $20) / $20 = 80%.

    Two things improve relative to the base case: earnings per share and the multiple applied to them. The $36 result requires both assumptions.

    Bear Case: $10.80

    Suppose weaker demand reduces revenue 10% to $90 million. Competitive pressure and underused capacity contribute to an assumed 8% net margin. Investors pay 15 times earnings because the outlook has weakened.

    Net income: $90 million × 0.08 = $7.2 million.
    EPS: $7.2 million / 10 million shares = $0.72.
    Implied price: $0.72 × 15 = $10.80.
    Price return: ($10.80 − $20) / $20 = −46%.

    Interpreting the Base, Bull, and Bear Results

    The bull case adds $36 − $20 = $16 per share, while the bear case removes $20 − $10.80 = $9.20. That shows an asymmetric set of selected payoffs. It does not establish that the stock offers an attractive expected return.

    No probabilities have been estimated. Averaging the three prices would impose equal weights without evidence. Calculating an expected value requires defensible probabilities and appropriate coverage of possible outcomes; selecting three cases does not supply either.[1]

    The base case is a reference point, not automatically the average or most likely result. Use the cases to identify what must go right, what could go wrong, and which assumptions most affect your decision.

    Scenario Analysis vs. Sensitivity Analysis

    A common sensitivity test changes one input while holding the others fixed. It isolates the model’s response to that assumption. Scenario analysis instead evaluates a set of assumptions representing specified business conditions.[5]

    Scenario Analysis

    • Asks what happens under a particular business story.
    • Changes a connected set of assumptions.
    • Example: stronger demand, a higher margin, and a different year-end P/E.

    One-Variable Sensitivity Analysis

    • Asks how much one assumption changes the answer.
    • Holds the other inputs constant.
    • Example: change only P/E while keeping base-case EPS.

    For a sensitivity test, keep base EPS at $1.10 and raise only P/E from 20 to 24. The price moves from $1.10 × 20 = $22 to $1.10 × 24 = $26.40. It does not reach the $36 bull result because the operating assumptions have not changed.

    The applications also differ. Portfolio stress testing examines exposure to crisis conditions, while the First Chicago Method applies explicit probability weights to startup outcomes. This example focuses on a company’s operating assumptions and implied stock price.

    How to Build Useful Scenarios

    1. Set the question and horizon. Identify the price date, starting financial results, earnings definition, and share count. Use the same basis in every case.
    2. Choose the business drivers. Start with demand, pricing, costs, and capacity rather than arbitrary percentage changes. A forecast should reflect how those drivers connect through the business.[7]
    3. Write a short explanation for each case. Ask whether the inputs can coexist. Higher growth might require discounts that reduce margins; a bull case should not simply maximize every favorable input.[1]
    4. Justify the valuation multiple. Use comparable companies analysis and the company’s history as reference points, while considering differences in fundamentals.[3] Growth expectations, interest rates, and perceived risk can affect multiples; stronger sales alone do not establish a higher P/E.[6]
    5. Reconcile and update. Check revenue through net income, EPS, price, and return. Then compare new results with the assumptions, recording what changed and why.

    Make the last step concrete. Check reported revenue, management’s price and volume explanations, margins, average shares, and relevant operating measures where available. Financial-statement notes and management’s discussion and analysis provide context for those figures.[2] This is part of ongoing fundamental analysis, rather than a one-time target-setting exercise.

    What Real Companies Show About Margins

    Historical results illustrate why revenue and margins need separate assumptions. These observations are not forecasts or valuations of either company.

    Microsoft: Revenue and Net Margin Increased

    For the fiscal year ended June 30, 2023, Microsoft reported revenue of $211.915 billion and GAAP net income of $72.361 billion. For fiscal 2024, revenue was $245.122 billion and net income was $88.136 billion.[8]

    Calculated net margin rose from $72.361 billion / $211.915 billion × 100 = 34.15% to $88.136 billion / $245.122 billion × 100 = 35.96%, rounded. Sales growth and margin expansion occurred together, but those results alone do not establish a future growth rate or P/E.

    Tesla: Revenue Increased While Operating Margin Fell

    Tesla’s 2023 Form 10-K reported revenue rising from $81.462 billion in 2022 to $96.773 billion in 2023. Operating income fell from $13.656 billion to $8.891 billion.[9]

    Operating margin therefore declined from $13.656 billion / $81.462 billion × 100 = 16.8% to $8.891 billion / $96.773 billion × 100 = 9.2%, rounded. Tesla’s Form 10-K separately described automotive delivery growth alongside lower selling prices, and identified pricing pressure in automotive gross margins.[9]

    Those are operating margins, not the net margins used in the hypothetical valuation. The lesson is to investigate the relevant costs and pricing tradeoffs before assuming that higher sales will lift the margin you are forecasting.

    Common Mistakes in Scenario Analysis

    • Starting with a desired price target. Build and support the operating assumptions before deciding whether the resulting price is appealing.
    • Combining incompatible inputs. Explain how rapid growth, pricing, capacity, and costs fit together. Favorable numbers in every column do not make a plausible bull case.
    • Assigning probabilities by label. Base does not automatically mean most likely, and three cases do not automatically deserve equal weights.
    • Mixing earnings and margin definitions. Keep net income separate from operating profit, and match the P/E to the earnings period and accounting basis being used.
    • Ignoring share changes. The example holds shares fixed. Issuance, repurchases, and dilutive instruments require attention when projecting per-share earnings.
    • Treating the output as a promise. The table estimates future prices conditional on assumptions. It neither establishes today’s intrinsic value nor guarantees a minimum or maximum future price.

    Limitations of Scenario Analysis

    Selected Cases Do Not Bound Reality

    The $10.80 bear price is the result of one adverse set of assumptions. Other conditions could produce a lower price. Likewise, $36 is not a ceiling. The table is not a confidence interval or a complete distribution of possible outcomes.

    Scenario selection is judgmental. Omitted drivers, unreliable forecasts, and inconsistent assumptions can make even perfectly reconciled results misleading.[1] The table also describes endpoints, not the price path between today and year-end.

    The chosen valuation method has limits. Zero or negative EPS makes the usual positive-P/E comparison unsuitable, and unusual earnings can distort a multiple.[3] Profit also differs from cash generation.[2] Depending on the business, a discounted cash flow analysis may provide a useful additional perspective.

    Frequently Asked Questions


    The base case is a central reference, the bull case is a favorable plausible path, and the bear case is an adverse plausible path. Each should explain its business and valuation assumptions. These labels alone supply neither probabilities nor outcome limits.


    Not automatically. Here, the base case produces a conditional 10% price gain. An expected return requires probability estimates across adequately specified outcomes; none are supplied for these cases. The base case can be an analyst’s central forecast without being a probability-weighted average.


    Start with relevant peer and historical multiples, then explain differences in growth prospects and risk. Match the multiple to the EPS definition and period. The example’s 20, 24, and 15 multiples are hypothetical assumptions, not universal base, bull, and bear settings.


    Yes. The bear case tests selected adverse assumptions; it does not identify every possible loss. Lower earnings, a lower multiple, or an omitted event could produce a worse outcome. Revisit the assumptions when evidence changes rather than treating the bear estimate as protection.


    Scenario analysis evaluates a connected business story. A one-variable sensitivity test isolates the effect of changing one input. Holding EPS at $1.10 while changing P/E to 24 produces $26.40; reaching the $36 bull price also requires the higher bull-case EPS.


    You can still build business scenarios, but the positive-P/E method illustrated here is unsuitable for losses. Do not interpret negative EPS multiplied by an arbitrary positive P/E as a meaningful share value. Choose a valuation framework appropriate to the business and its path to future earnings or cash flows.

    Sources

    Sources consulted October 20, 2026. The three-case valuation and sensitivity test are hypothetical; the Microsoft and Tesla observations are dated historical examples.

    1. Aswath Damodaran, NYU Stern, Probabilistic Approaches: Scenario Analysis, Decision Trees and Simulations, especially printed pages 2–4 and 8–9.
    2. U.S. SEC, Beginners’ Guide to Financial Statement, February 2007; income statements, EPS, ratios, cash flows, footnotes, and MD&A.
    3. CFA Institute, Market-Based Valuation: Price and Enterprise Value Multiples, 2026 public summary; earnings definitions, benchmarks, and terminal-value expressions.
    4. Microsoft, 2024 Annual Report, Note 2, Earnings Per Share.
    5. OpenStax, Forecasting Cash Flow and Assessing the Value of Growth, Principles of Finance, section 18.5; scenarios and sensitivity analysis.
    6. CFA Institute, Economics and Investment Markets, 2026 public summary; factors affecting P/E.
    7. CFA Institute, Introduction to Financial Statement Modeling, 2026 public introduction and learning outcomes.
    8. Microsoft, FY24 Q4 Earnings Release, July 30, 2024; full-year GAAP results for fiscal 2023 and 2024.
    9. Tesla, 2023 Form 10-K, Item 8, Consolidated Statements of Operations, printed page 50; Item 7, automotive revenue and gross-margin discussions, printed pages 38–40.
    Disclaimer

    This article is for educational purposes and does not constitute investment advice. The valuation example is hypothetical and simplified. Scenario results depend on assumptions and do not guarantee future prices or returns.

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