Three-Statement Financial Modeling 三表財務建模
Released已發布Build three-statement financial models (Income Statement, Balance Sheet, Cash Flow) with revenue forecasting, assumption management, and scenario analysis. Use this skill when the user needs to project financials, build a fundraising model, create financial projections for a business plan, or evaluate M&A targets — even if they say 'build a financial model', 'project our revenue', 'how much money will we make next year', or 'model this acquisition'.
金融技能:Three-Statement Financial Modeling 分析與應用。
Assumptions前提假設
| Assumption | Y1 | Y2 | Y3 | Y4 | Y5 | Source |
|---|---|---|---|---|---|---|
| Revenue growth | {%} | {%} | {%} | {%} | {%} | {basis} |
| Gross margin | {%} | ... | ... | ... | ... | ... |
| OpEx growth | {%} | ... | ... | ... | ... | ... |
Framework 框架
IRON LAW: The Three Statements Must Balance
Assets = Liabilities + Equity (Balance Sheet identity)
Net Income flows from IS to BS (retained earnings)
Cash flow bridges IS and BS through working capital and capex
If your model doesn't balance, there's an error. Check the cash line on
the BS against the ending cash on the CF statement. They MUST match.
Model Architecture
[Assumptions Page] → drives everything
↓
[Income Statement] → Revenue, costs, taxes → Net Income
↓
[Balance Sheet] → Assets, liabilities, equity → must balance
↓
[Cash Flow Statement] → Start cash + Operating + Investing + Financing = End cash
↓
[Outputs: DCF, Returns, Scenarios]
Revenue Forecasting Methods
| Method | How | Best For |
|---|---|---|
| Top-down | Market size × market share × price | New markets, macro-driven |
| Bottom-up | Units × price, or customers × ARPU | Established products, SaaS |
| Run-rate | Current monthly × 12, adjusted for growth | Near-term projections |
| Cohort-based | New cohort revenue + existing cohort retention | Subscription businesses |
Key Assumptions to Document
| Category | Assumptions |
|---|---|
| Revenue | Growth rate, pricing, volume, churn (if subscription) |
| COGS | Gross margin trajectory, input cost inflation |
| OpEx | Headcount plan, salary inflation, marketing as % of revenue |
| Working Capital | DSO (days sales outstanding), DPO (days payable), DIO (days inventory) |
| CapEx | Capital expenditure as % of revenue or specific projects |
| Tax | Effective tax rate, tax loss carryforwards |
| Financing | Debt schedule, interest rates, equity raises |
Building Steps
Phase 1: Assumptions
- Document all assumptions on a dedicated page
- Color code: blue = input, black = formula, green = linked from another sheet
- Each assumption must have a source or rationale
Phase 2: Income Statement 4. Build revenue line from assumptions 5. COGS and gross profit 6. Operating expenses by category 7. EBITDA, depreciation, EBIT 8. Interest, taxes, net income
Phase 3: Balance Sheet 9. Working capital items from IS drivers (DSO × Revenue/365, etc.) 10. Fixed assets: prior period + capex - depreciation 11. Debt schedule: prior period + new borrowing - repayment 12. Equity: prior period + net income - dividends + equity raises 13. CHECK: Assets = Liabilities + Equity
Phase 4: Cash Flow 14. Start with net income 15. Add back non-cash items (depreciation, amortization) 16. Working capital changes (from BS period-over-period) 17. CapEx (investing) 18. Debt and equity changes (financing) 19. CHECK: Ending cash = BS cash line
Phase 5: Scenarios 20. Base case (most likely assumptions) 21. Bull case (optimistic — higher growth, better margins) 22. Bear case (pessimistic — lower growth, margin pressure)
Output Format輸出格式
# Financial Model: {Company} — {Projection Period}
Gotchas注意事項
- Revenue is the most sensitive assumption: A 2% difference in growth rate compounds enormously over 5 years. Always present a range, not a point estimate.
- Working capital is often forgotten: Fast-growing companies consume cash in working capital (building inventory, extending credit). A profitable company can run out of cash if working capital isn't modeled.
- Circular references with interest: Interest expense depends on debt balance, which depends on cash (which may require more debt). Break the circularity with an iterative calculation or prior-period debt balance.
- Granularity should match certainty: Model Year 1 monthly, Year 2 quarterly, Years 3-5 annually. Detailed monthly projections for Year 5 are false precision.
- Assumptions page is the most important page: Nobody should need to dig into formulas to understand what drives your model. All assumptions visible, documented, and changeable in one place.
References參考資料
- For DCF valuation built on the three-statement model, see the biz-dcf skill
- For spreadsheet best practices, see
references/modeling-best-practices.md