Cost of Capital, Required Return, and Peer Capital Structure

How Level II tests advanced cost-of-capital estimation, required return, private-company adjustments, and capital-structure comparison.

At Level II, cost of capital is not just a memorized WACC formula. The exam is more interested in whether you can estimate the right input for the right issuer, judge the difference between public and private company estimation, and compare a company’s financing mix with peers in a way that actually informs valuation.

Why This Lesson Matters

Candidates often default to a single mechanical approach. The exam pushes harder:

  • should cost of debt come from market yields, credit spreads, or accounting numbers?
  • should required return on equity come from CAPM, a build-up approach, or another proxy?
  • how should private-company estimation differ from public-company estimation?

Start With The Estimation Choice

    flowchart TD
	    A["Need issuer cost of capital"] --> B["Estimate cost of debt"]
	    A --> C["Estimate required return on equity"]
	    A --> D["Evaluate capital structure relative to peers"]
	    B --> E["Use market yield or spread based debt view"]
	    C --> F["Use public market model or private company proxy"]
	    D --> G["Judge leverage risk tax shield and strategic fit"]

The exam often tests whether you picked the right estimation path before it tests the arithmetic.

Cost Of Debt And Cost Of Equity Are Separate Problems

After-tax cost of debt is commonly expressed as:

$$ r_d(1-T) $$

and a CAPM-style required return on equity is:

$$ r_e = r_f + \beta (ERP) $$

Weighted average cost of capital is then:

$$ WACC = w_d r_d(1-T) + w_e r_e $$

InputWhat the exam wants you to judge
(r_d)Is the debt estimate current and market-based enough?
(T)Is the relevant tax shield assumption reasonable?
(r_e)Does the equity model fit the issuer and data available?
WeightsAre the capital weights consistent with target or market structure?

Top-Down And Bottom-Up Drivers Both Matter

Driver typeExamples
Top-downRisk-free rates, market risk premiums, macro regime, credit-market conditions
Bottom-upBusiness risk, leverage, operating stability, asset mix, competitive position

Level II often gives one top-down and one issuer-specific clue and asks which one actually changes the cost of capital estimate more.

Public And Private Company Estimation Should Not Be Treated The Same Way

Issuer typeTypical challenge
Public companyMarket prices and betas exist, but may still need judgment
Private companyNo directly observed beta or market equity return, so peer-based or build-up methods matter more

The exam often tests whether the candidate knows that private-company required return estimation usually leans more heavily on comparable firms and judgmental adjustments.

Peer Capital Structure Comparison Is Not A Beauty Contest

When comparing capital structure with peers, the real question is whether the issuer’s leverage:

  • fits the stability of its business model
  • remains manageable under stress
  • is above or below what similar firms can support efficiently
If leverage is higher than peersPossible implication
Strong cash-flow stabilityMay be reasonable or even efficient
Weak or cyclical cash flowMay signal elevated financing risk and a fragile WACC assumption

How CFA-Style Questions Usually Test This

  • by asking which method best estimates the cost of debt or equity in the scenario
  • by asking how a change in macro conditions affects WACC inputs
  • by asking how to estimate required return for a private company
  • by comparing one company’s leverage and cost of capital with peer issuers

Mini-Case

A private company in a cyclical industry is being valued using a public-company beta from a much larger, more diversified peer group with lower leverage.

A weak answer applies the peer beta directly and moves on.

A stronger answer questions comparability and recognizes that business risk, leverage, and private-company estimation constraints all need to be addressed before treating that required return as reliable.

Common Traps

  • using book rather than economically relevant market weights without justification
  • confusing historical borrowing cost with current marginal cost of debt
  • treating CAPM as automatically sufficient for private-company equity estimation
  • comparing leverage to peers without considering business-model stability

Sample CFA-Style Question

Why might a company’s WACC appear low even when its capital structure is risky?

Best answer: Because increased debt weight and tax-shield effects can mechanically lower WACC estimates even when the firm’s business and financing risk are becoming less sustainable.

Why: Level II often tests whether the candidate sees that a lower modeled WACC is not automatically a sign of better capital structure quality.

Continue In This Chapter

Revised at Thursday, April 9, 2026