Free Cash Flow (FCF)

Free cash flow equals operating cash flow minus capital expenditures. Operating cash flow starts with net income and adjusts for non-cash items (depreciation, amortization, stock-based compensation) and changes in working capital. Subtracting capex produces the cash available after the company has maintained and invested in its asset base -- the number that can actually be returned to shareholders, used to repay debt, or reinvested in growth. This is why Warren Buffett's 'owner earnings' concept -- approximately operating income plus depreciation minus maintenance capex -- closely tracks free cash flow as the more economically honest measure of what a business actually earns.

Accounting earnings have multiple escape hatches that allow management to influence reported profitability: revenue recognition timing, depreciation schedules, capitalization versus expensing decisions, and reserve levels. Free cash flow has fewer. Cash collected from customers is cash; cash paid to suppliers and employees is cash. The primary manipulation available in operating cash flow is working capital management -- stretching payables (taking longer to pay suppliers) and accelerating receivables (collecting from customers faster) can temporarily boost cash flow. But these levers are limited by supplier relationships and customer terms, and the effect reverses in subsequent periods.

The gap between net income and FCF is an informative signal in both directions. A business that generates significantly more FCF than net income -- because depreciation charges exceed maintenance capex needs -- is producing accounting earnings that understate real cash generation. Many asset-light businesses (software, consumer brands) fall into this category. Conversely, a business where net income consistently exceeds FCF is consuming cash to grow -- which is fine for a rapidly expanding company building competitive infrastructure, and a warning sign for a mature company with limited growth requiring disproportionate cash consumption.

FCF yield -- free cash flow per share divided by the current share price -- translates FCF generation into a valuation metric directly comparable to a bond yield. A stock with a 7% FCF yield is generating 7 cents of free cash flow for every dollar of share price. Whether that is cheap or expensive depends on the growth rate of that cash flow and the alternative investment landscape. In a 5% risk-free rate environment, a 7% FCF yield with 3-4% growth is modestly attractive. In a 1% rate environment, it is highly compelling.

FCF yield screens are particularly useful for identifying capital return capacity. A company with 8-10% FCF yield, a clean balance sheet, and shareholder-friendly management has the capacity to return 6-8% of market cap annually through dividends and buybacks while still investing in organic growth -- a powerful compounding setup. The discipline of tracking FCF yield consistently prevents the mistake of paying excessive prices for businesses whose earnings are accounting constructs rather than cash realities. Some of the most expensive mistakes in equity investing have involved paying 40-50x earnings for businesses with FCF yields of 1-2%, assuming earnings would eventually translate into cash that never arrived.

FCF conversion rate -- FCF as a percentage of net income -- is the simplest summary of earnings quality. A conversion rate of 90-110% indicates high-quality earnings where cash and accounting are closely aligned. Persistent rates below 70% warrant investigation: where is the cash going? Sustained rates above 110% indicate the accounting is being conservative relative to cash reality, which can signal hidden value in assets being depreciated faster than they wear out.