Free Cash Flow

Free cash flow is the cash a business generates after paying for the capital assets that keep it running, and the formula is short: cash from operations minus capital expenditures. Both inputs sit on the cash flow statement of every filed annual and quarterly report. What remains is the cash genuinely available to owners — to pay dividends, repurchase shares, retire debt, or fund acquisitions — without borrowing or selling anything.

The first input, cash from operations, is the cash that actually arrived from customers minus the cash that actually left for suppliers, employees and the tax authority. It differs from net income because accrual accounting records revenue when it is earned and costs when they are incurred, not when money moves. Depreciation, a large non-cash charge, is added back; swings in receivables, inventory and payables are folded in. The second input, capital expenditure, appears lower down under investing activities — the payments made to buy and maintain property, plant and equipment. Subtracting it matters because the depreciation added back in the first step reflects real machines that really wear out and really must be replaced with cash.

Why not simply use net income? Because earnings are an opinion about which period a cost belongs to, while cash is a fact. A company can report growing profits while its customers pay ever later, its inventory piles up, and every dollar of profit is consumed by new equipment. Free cash flow catches all three. That is why value investors treat it as the harder-to-manage sibling of earnings: over a decade the two should tell roughly the same story, and when they persistently diverge, the cash flow statement is usually the one telling the truth.

What does good look like? A mature business converting most of its net income into free cash flow, year after year. Warren Buffett's "owner earnings" — reported earnings plus depreciation and amortisation, minus the capital spending required to maintain competitive position — is the same idea stated more precisely. The standard formula uses total capital expenditure because filings do not separate maintenance spending from growth spending, which makes it deliberately conservative: a company investing heavily at high returns will show depressed free cash flow even while it is creating value. Amazon spent the better part of two decades looking poor on this measure while building the machine that later produced the cash.

The failure modes run in both directions. Free cash flow can be flattered for a year or two by starving capital spending, stretching payables, or collecting receivables aggressively — none of which is repeatable. It can be understated by a genuine investment surge. Stock-based compensation deserves particular attention: it is added back inside operating cash flow as a non-cash cost, yet it dilutes shareholders as surely as a cash expense, so a business that pays its people heavily in shares reports better free cash flow than its owners actually experience. A single year of the figure is noise; a run of five to ten years is signal.

Sector context changes the reading. For banks and insurers the formula is close to meaningless — lending and underwriting move cash for reasons unrelated to plant and equipment, which is why balance-sheet measures such as book value carry more weight there. Real estate investment trusts substitute funds from operations, because property depreciation dominates their income statements. And comparing an asset-light software firm's free cash flow margin with a railroad's tells you mostly about their industries, not their managements.

Moatkeep computes free cash flow exactly as the formula states: cash from operations minus capital expenditures, both taken from each company's own SEC filings, summed over the trailing twelve months and revised whenever a company restates. The figure feeds the per-share value, the growth series and the free cash flow yield shown across the site, each stamped with the fiscal period it was computed from. When trailing free cash flow is negative, the ratios built on it display as not meaningful rather than as a misleading negative multiple.

The reason a value investor starts here is Buffett's old question: if you owned the whole business, how much cash could you take out each year without harming it? Free cash flow is the filed-accounts approximation of that number. It is not a valuation by itself — a price still has to be paid for it — but it is the numerator that survives contact with reality better than any other.