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ISSUE 001SUMMER 2026

IBT-5INVESTMENT BANKING TECHNICAL CHAPTER 6 OF 13REVIEWED 2026-07-31

DCF: forecast cash and expose the assumptions

A DCF is useful only when its operating logic, reinvestment, terminal value, and discount rate survive review.

The formula is the easy part. The value comes from a coherent operating model and honest sensitivity.

WHAT THIS CHAPTER TEACHES

  • Build revenue from operational drivers where possible, then forecast margins, taxes, depreciation, capital spending, and working capital.
  • Define unlevered free cash flow consistently and explain each adjustment.
  • Build WACC from dated inputs and transparent choices for risk-free rate, equity risk premium, beta, debt cost, tax, and capital weights.
  • Use exit-multiple or perpetual-growth terminal value, then test the implied assumptions.
  • Compare implied multiples, margins, growth, reinvestment, and returns on capital with history and peers.

The DCF question

A discounted cash-flow analysis estimates the present value of cash generated by the operating business. It requires an operating forecast, a cash-flow definition, a discount rate, and a terminal value. Every component should be connected to business economics rather than selected to reach a desired answer.

Forecast period

The explicit period should be long enough for the company to move from its current state toward a more stable operating state. Five years is common but not mandatory. A business in a major capacity build, turnaround, or rapid-growth phase may need a longer period. Forecasting farther doesn't create more information; it increases the number of assumptions.

Revenue forecast

Use operating drivers when possible. Revenue can be customers × price, units × volume, stores × sales per store, capacity × utilization × price, or another business-specific relationship. Segment the forecast when products have different growth and margin profiles.

Profitability and reinvestment

Forecast gross margin and operating expenses based on operating logic. Distinguish fixed, variable, and step costs. Reinvestment includes capital expenditures, working capital, research, customer acquisition, and other spending required to sustain growth. A forecast that grows revenue without funding the growth overstates cash.

Unlevered free cash flow

A common definition is:

EBIT × (1 − cash tax rate) + depreciation and amortization − capital expenditures − increase in net working capital, adjusted for other operating items as appropriate.

Use a consistent treatment for stock compensation, leases, restructuring, pensions, and acquisition-related items. Explain whether the cash flow reflects the business as currently financed or a normalized capital structure.

Weighted average cost of capital

WACC combines the cost of equity and after-tax cost of debt using target market-value weights. The cost of equity commonly uses a risk-free rate, beta, and equity risk premium, sometimes with additional risk adjustments. The cost of debt should reflect current borrowing economics for the company or a relevant target structure.

Each input has judgment. Beta depends on the peer set, period, frequency, leverage, and re-levering. The equity risk premium varies by method and market. Target capital structure may differ from the current balance sheet. Date every market input.

Terminal value

The perpetuity-growth method capitalizes the next period’s cash flow using WACC minus long-term growth. The growth rate must be economically sustainable and consistent with inflation, reinvestment, and returns on capital.

The exit-multiple method applies a market multiple to a terminal metric. The multiple should be consistent with the company’s terminal growth, margin, risk, and current comparable evidence. It doesn't avoid assumptions; it expresses them differently.

Midyear convention and present value

Cash is generated through the year rather than entirely at year-end. A midyear convention can better approximate timing. Be consistent in the terminal-value timing and discount periods.

Enterprise-to-equity bridge

The present value of unlevered cash flow and terminal value produces enterprise value. Add nonoperating assets and subtract debt and other claims to reach equity value. Divide by diluted shares for an implied value per share when relevant.

Sensitivity and scenarios

At minimum, sensitize WACC and terminal growth or exit multiple. More useful scenarios also vary operating drivers. A two-way table can show model sensitivity, but a narrative scenario explains how the business gets there.

DCF diagnostics

Review terminal value as a percentage of enterprise value, implied terminal multiple, revenue and margin path, reinvestment, return on invested capital, and the relationship between growth and cash. If most value comes from a terminal assumption inconsistent with the operating forecast, the model isn't internally coherent.

Common errors

  • using EBITDA as cash flow without reinvestment or tax;
  • using current debt weights when the model assumes a different target structure;
  • subtracting debt twice;
  • mixing nominal cash flows with a real discount rate;
  • using an unsustainable perpetual growth rate;
  • applying an exit multiple that assumes better economics than the terminal forecast;
  • presenting one value without sensitivity;
  • changing assumptions to match a target price.
CURRENT AS OF 2026-07-31

DCF market inputs are date-sensitive. Industry data sources can support beta, risk-premium, and capital-structure work, but the analyst should document the selected methodology and reconcile it to the valuation date.

SOURCES

  1. 01SEC: How to Read a 10-K/10-Q
  2. 02SEC: Beginners Guide to Financial Statements
  3. 03SEC: Financial Statement Data Sets
  4. 04SEC: Form 10-Q
  5. 05SEC: Financial Reporting Manual
  6. 06SEC: SPAC compliance guide
  7. 07FINRA: Understanding Settlement Cycles
  8. 08Capital One: Discover announcement
  9. 09Capital One/Discover definitive proxy
  10. 10Capital One: Discover completion
  11. 11NYU Stern — Aswath Damodaran data and valuation resources
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