TL;DR: ROE tells you how much return shareholders are getting on their equity, but the number alone is not enough. Use DuPont Analysis to break ROE into three components and find out whether a high return is driven by real business strength or propped up by leverage.
Concepts
What Is ROE? Why Does It Matter?
The formula for ROE (Return on Equity):
ROE = Net Income / Shareholders' Equity x 100%
In plain terms, it answers: for every $100 shareholders have invested, how much does the company earn in a year? An ROE of 20% means the company earns $20 for every $100 of equity.
Warren Buffett has said that ROE is the metric he values most. Companies that consistently maintain a high ROE over time typically possess a strong competitive advantage. Generally, an ROE that stays above 15% is considered excellent.
But here is the catch: two companies can both have an ROE of 20%, yet their earnings quality can be vastly different. That is why we need DuPont Analysis.
DuPont Analysis: Breaking ROE Apart
DuPont Analysis decomposes ROE into three components:
ROE = Net Profit Margin x Asset Turnover x Equity Multiplier
Each component represents a different capability:
- Net Profit Margin: How much profit remains out of every $100 in revenue. Represents profitability.
- Asset Turnover: How much revenue the company generates from its assets. Represents operational efficiency.
- Equity Multiplier: How much leverage the company uses. Formula: Total Assets / Shareholders' Equity. Represents financial leverage.
Good vs. Bad High ROE
Consider two examples:
Company A: ROE 20% = Net Margin 20% x Turnover 0.8 x Equity Multiplier 1.25 This is driven by high profit margins with low leverage -- the healthiest type of high ROE.
Company B: ROE 20% = Net Margin 5% x Turnover 1.0 x Equity Multiplier 4.0 Low profit margins, propped up by heavy leverage (lots of debt) -- a high-risk ROE.
Both have an ROE of 20%, but Company A's quality is far superior. This is the value of DuPont Analysis: it helps you see the truth behind the numbers.
The ideal high-ROE profile is: high net margin + reasonable asset turnover + low leverage. TSMC is a classic example of a margin-driven ROE, sustained by its technological moat and high gross margins rather than by borrowing.
Hands-On: Using CTSstock
- Go to
/analysis/2330(using TSMC as an example) - Click the Financial Ratios tab at the top
- Find the DuPont Analysis section
- You will see ROE decomposed into net profit margin, asset turnover, and equity multiplier
- Key things to watch:
- Has ROE been consistently above 15% over time?
- Which of the three components is the main driver?
- Is the equity multiplier trending upward (indicating increasing debt)?
- How are net margin and turnover trending over time?
FAQ
Q: Is a higher ROE always better? A: Not necessarily. If a high ROE is driven by heavy borrowing (a high equity multiplier), the risk is significant. Always use DuPont Analysis to examine the three components and determine whether the ROE is genuinely earned.
Q: What is a reasonable equity multiplier? A: It depends on the industry. For general manufacturing, 1.5-2.5 is considered normal. Financial institutions inherently operate with high leverage and may have multipliers above 10. The key is that the trend should not be steadily climbing.
Q: What is the difference between ROE and ROA? A: ROA (Return on Assets) = Net Income / Total Assets, and it does not account for leverage. The larger the gap between ROE and ROA, the more leverage the company is using. Looking at both together gives you a clearer picture of the earnings structure.