Wacc

$$w_E\cdot (r_f+\beta \cdot \text{ERP})+w_D\cdot \frac{\text{Interest expense}}{\text{Total debt}}\cdot (1-\text{tax rate})$$

Weighted average cost of capital. Cost of equity via CAPM (risk-free rate + beta × equity risk premium); cost of debt as interest expense divided by total debt, after the corporate tax shield. Weights from market cap of equity and book value of total debt.

Direction: Lower better Category: returns

Inputs (XBRL fallback chains):

• interest_expense: InterestExpense -> InterestExpenseDebt -> InterestExpenseOperating -> InterestExpenseBorrowings
• long_term_debt: LongTermDebt -> LongTermDebtNoncurrent
• short_term_debt: ShortTermBorrowings -> DebtCurrent -> LongTermDebtCurrent

Returns None when: Returns None when beta (from companies.beta_5y_monthly_vs_spy) or market cap is missing. Zero-debt firms contribute only the equity term. Default rf 4%, ERP 5%, tax 21%.

Source code

Implementation: wacc in src/eqtytrk/metrics/ratios.py (or valuation.py for multiples).