Earnings answer one question. Free cash flow answers another, often more practical one. Mechanism: Accrual accounting is useful, but cash conversion is what tells you how much of the story is available to reinvest, defend the balance sheet or return to owners. Why it matters: The gap between earnings and cash flow is where a lot of business quality analysis actually begins. Market translation: If receivables and stock-based compensation are doing too much of the work, the headline EPS may be less informative than it looks. Failure mode: The mistake is treating clean-looking EPS as the end of the analysis. Review question: Write down the state variable you would monitor first if this thesis started to drift. That is usually where the edge is: not in the vocabulary, but in the structure underneath it.