A 25% ROE looks great until you decompose it. Sometimes it's a dominant moat throwing off cash; sometimes it's a leveraged-up balance sheet pretending to be profitable. DuPont decomposition answers which of those you are buying. ROIC goes one step further and removes the leverage trick entirely.
The DuPont Three-Factor Form
ROE = (Net Margin) × (Asset Turnover) × (Equity Multiplier)
That is: profitability × efficiency × leverage. The same ROE can come from very different mixes — and the mix tells you what kind of business you actually own.
Why ROIC Is the Cleaner Quality Test
ROIC = NOPAT / Invested Capital — the return on every dollar invested in the business, regardless of whether it came from equity or debt. ROIC strips out the leverage trick: a company that goosed ROE with debt can still have a mediocre ROIC. The only sustainable quality test is ROIC > cost of capital — that is the spread that creates real shareholder value over time.
Field-Test Routine
- Pull 5 years of net margin, asset turnover, and equity multiplier. Plot them as three lines.
- Identify which factor is doing the heavy lifting. Margin-driven = pricing power story. Turnover-driven = scale / efficiency story. Leverage-driven = financial engineering, treat with caution.
- Compute ROIC alongside. If ROIC has been > the company's cost of capital for 5+ years, the moat is real. If ROIC < cost of capital while ROE looks fine, the business is destroying value at the enterprise level — equity holders are just last in line to feel it.
ROE = Margin × Turnover × Leverage
Same ROE can come from very different business models — decompose to know which
ROIC > cost of capital is the only durable test of quality