DUOL Fundamental Analysis

Fundamental analysis is the discipline of estimating what a business is worth by examining the financial evidence it produces: how much it earns, how efficiently it converts revenue to cash, how much capital it uses to produce those earnings, and whether the current price compensates an investor for the risks of holding it. The metrics on this page are organized into six evidence buckets -- valuation, profitability, leverage, growth, efficiency, and company size -- because each bucket answers a different question. Valuation multiples answer whether the market price is cheap or expensive relative to underlying earnings power. Profitability answers whether the business model is inherently strong or thin. Leverage answers whether the balance sheet is durable under stress. No single ratio tells a complete story; the analysis is about how the full set hangs together.

The single most diagnostic question in fundamental analysis is whether a business generates returns on invested capital above its cost of capital. A business that earns 20% ROIC while its cost of capital is 9% is compounding value for shareholders at an 11-point spread -- and the market will typically pay a meaningful premium to book value for that privilege. A business that earns 8% ROIC against a 10% cost of capital is destroying economic value even if reported earnings are growing, because growth at below-cost returns dilutes per-share value rather than building it. This is why ROIC and gross margin -- which measures the inherent advantage in the product before overhead -- are the highest-signal fundamental metrics for evaluating business quality at the model level.

Valuation multiples (P/E, EV/EBITDA, P/S, P/FCF) measure what the market currently demands per unit of earnings, sales, or cash flow. They are not independently actionable: a low P/E can indicate value or distress, and a high P/E can indicate genuine quality or speculative excess. The interpretive work is contextual -- comparing a multiple to sector peers, to the company's own history, and to the underlying growth rate. The PEG ratio (P/E divided by earnings growth rate) is a simple first-order adjustment; EV/EBITDA is more reliable for cross-capital-structure comparisons because it normalizes for debt. FCF yield (FCF / market cap) is the cleanest single valuation signal for mature businesses because it is harder to manipulate than GAAP earnings.

Growth metrics deserve careful handling. Revenue growth that outpaces earnings growth signals margin compression -- revenue expansion without profitability improvement. EPS growth that outpaces revenue growth often reflects share buybacks rather than operational leverage, which is worth distinguishing. The highest-quality growth signature is expanding ROIC alongside revenue growth: the business is finding new markets without sacrificing the economics that made the existing business attractive. Declining ROIC with accelerating revenue growth is the opposite -- scale without economics, often the precursor to a valuation reset.