S&P 500 companies just posted a blended net profit margin of 16.9% in Q2 2026 — the highest reading since FactSet began tracking the metric in 2009, up from 12.9% a year earlier and well above the five-year average of 12.4%. That's a genuinely strong number, but margin is only one-third of the story behind a company's return on equity. DuPont analysis is the tool that separates a stock whose ROE is earned through real operating strength from one that's simply borrowing its way to a good-looking number.
The three-factor formula
Return on equity, in its plain form, is just net income divided by shareholder equity. DuPont analysis — developed inside the DuPont chemical company in the 1920s to evaluate its own divisions — rewrites that single number as three factors multiplied together: ROE = Net Profit Margin × Asset Turnover × Equity Multiplier.
Net profit margin (net income ÷ revenue) captures operating efficiency — how much of every sales dollar the company actually keeps. Asset turnover (revenue ÷ total assets) captures how productively the balance sheet is being used to generate sales. The equity multiplier (total assets ÷ shareholder equity) captures leverage — how much of the asset base is financed with debt rather than equity. Multiply all three and you land back on the exact same ROE a simple calculation would give you, except now you know which lever is doing the work.
Why one ROE number can hide two different companies
Two companies can post an identical 20% ROE for completely different reasons. A software company might get there with a 30% net margin, modest asset turnover, and almost no leverage — profit-driven, low financial risk. A regional bank or a heavily leveraged retailer might get to the same 20% with a thin single-digit margin and a large equity multiplier, meaning debt is doing most of the lifting. Both show "20% ROE" on a stock screener, but only one of them is earning it primarily through the business itself.
That distinction matters because leverage cuts both ways — it amplifies ROE in good years and losses in bad ones. A rising ROE driven by an expanding equity multiplier, with margin and turnover flat or falling, is a classic warning sign that a company is propping up its returns with debt rather than improving the underlying business.
Where the record margin fits in
The current 16.9% blended S&P 500 net margin is a big part of why index-wide ROE has held up even with rates well above the near-zero era of the 2010s. Higher margins mean companies need less leverage and less asset efficiency to produce the same return, which is a healthier setup than an ROE built primarily on debt. But margin strength isn't evenly distributed — a handful of mega-cap technology names contribute disproportionately to the index average, so screening for high-margin, high-ROE names individually still matters more than assuming the whole market looks like the aggregate number.
A more reliable way to screen for quality
Rather than trusting ROE in isolation, it's more reliable to filter for strong ROE and then cross-check with a margin filter — a company that clears both is earning its returns through profitability rather than leverage. That combination rules out the leverage-driven version of a "good" ROE number, which is exactly the kind of quality distinction a raw ROE screen misses.