AUTOZONE INC (AZO) stock intrinsic value fair value estimate & owner earnings analysis

AutoZone sells automotive replacement parts, maintenance items and accessories through about 6,600 stores in the United States, 880 in Mexico and 150 in Brazil, to both do-it-yourself drivers and professional repair shops (the commercial program runs from about 6,100 US stores). Sales were $18.9 billion in the year to August 2025 with a gross margin of 52.6%. Demand comes mostly from failure and maintenance repairs on an aging fleet of cars, which people cannot easily defer, so the business has historically held up well when the economy weakens. What the business earns. We measure the cash the owners actually keep: operating cash flow, with short-term swings in inventory and payables stripped out, less stock compensation and the capital spending needed to keep the store base in shape. Over the last five years (fiscal 2021 to 2025, the period that reflects today's larger, higher-margin business after the 2020-2021 step-up in sales) this came to between $89 and $121 a share each year, and $116 a share in fiscal 2025. Two accounting judgements matter. First, fiscal 2025 operating cash flow was held down by an $894 million build in inventory as AutoZone pushed more parts into hubs and mega-hubs; we treat that as timing, not lost earnings. Second, capital spending has more than doubled since 2021 to $1.33 billion, against depreciation of $613 million, as the company builds stores, mega-hubs and distribution centres. Because sales grew only 2-3% in the last two years, our method counts almost all of that spending as the cost of staying in business rather than growth investment. That is deliberately conservative: if part of today's building programme is truly expansion, earning power is higher than we assume. Before paying its lenders, the business produced about $2.4 billion of cash in fiscal 2025 ($2.0 billion for owners plus $413 million of interest paid), and the median of the last five years is the same $2.4 billion, roughly $143 per current share. That is our starting point. Business cash flow grew 6.7% in fiscal 2025; the first nine months of fiscal 2026 show sales up 8% but operating profit flat, held back by inventory cost charges and higher spending, so we start the base case at only 3% growth next year. Debt. AutoZone deliberately runs with about $9.0 billion of bonds and commercial paper plus $0.4 billion of finance leases, against $0.25 billion of cash, so net debt is about $9.2 billion. Shareholders' equity on the books is negative $2.8 billion; that is the accumulated result of buying back more stock than the company has retained in profits, not a sign of distress. The notes are a staggered ladder of fixed-rate issues mostly between 3% and 6.55% maturing from 2026 to 2034, interest is covered roughly five times by business cash flow, and the company targets an investment-grade rating, so we make no adjustment for the cost of the debt. About $3.4 billion of store leases are not deducted because rent is already paid out of the cash flows above. Base case: worth about $52.8 billion as a business, owes $9.2 billion, leaving about $43.6 billion or $2,588 a share. Growth comes only from what AutoZone has done for decades with its own cash: opening roughly 150-300 stores a year, adding mega-hubs and extending the commercial program, plus modest price increases in line with parts inflation. We credit 3% in year one, 4-4.5% for the following four years, tapering to 2% by year ten as the US store base matures, and then hold cash flow flat in dollars forever. Holding it flat means its value shrinks after inflation, which is how we account for the slow headwind from electric vehicles, which have fewer parts to fail (a risk the company itself discloses). We do not credit faster international growth, market-share gains or margin expansion. Bear case: worth about $29.6 billion, owes $9.2 billion, leaving about $20.4 billion or $1,212 a share. Car parts demand has not historically collapsed in recessions (AutoZone kept growing through 2008-2010), so the realistic hard downturn for this industry is a competitive and cost squeeze of the kind Advance Auto Parts suffered in 2023-2024, when its profits largely disappeared, and AutoZone's own 2017-2018 stall, when same-store sales were flat. We model business cash flow falling 10% and then a further 6% over two years from price competition and tariff-driven cost inflation, a partial recovery, growth of only 1.5% a year to year ten, and then a decline of 3% a year for thirty years as electric vehicles erode parts demand, after which we credit nothing. Even at the trough, cash flow of about $2.0 billion covers interest more than four times, so the debt is serviceable in this case. Bull case: worth about $68.1 billion, owes $9.2 billion, leaving about $58.9 billion or $3,496 a share. This assumes the mega-hub and commercial build-out pays off as the 2021-2023 period suggested, with growth of 6-6.5% for five years tapering to 3.5% by year ten, then 2% for another ten years as Mexico and Brazil keep adding stores at their current pace, then flat. Our previous analysis was built on a different basis and its figures are not comparable to these. Margin-of-safety price. We are fairly confident in the earnings level: five years of cash flow sit in a tight band around $2.4 billion and sales have grown every year for well over a decade. The biggest structural risk is the debt combined with a shrinking share count: AutoZone has chosen to keep borrowing to buy back stock, so if credit markets closed for an extended period it would have to stop repurchases and repay maturities from cash, which it could do from about two years of free cash flow; the business itself would survive that. The things we are most likely to be wrong about are how much of today's capital spending is really permanent, how fast electric vehicles reduce parts failures, and whether competitors such as O'Reilly, Amazon and Walmart squeeze margins. If all three went against us at once, the shares would be worth roughly the bear figure of about $1,200. While waiting, an owner receives no dividend but the business generates about $119 a share after interest, nearly all of it returned through buybacks that have shrunk the share count by about 5% a year over the past decade. At $1,350 that is close to a 9% cash yield before any growth. If the share price reaches our base value, which itself rises around 6-7% a year per share as buybacks continue, within four to five years, the shares would be worth roughly $3,300-3,500, about two and a half times the margin-of-safety price and consistent with a 20% annual return, while the bear case implies a loss of about 10%. Above roughly $1,350 that combination of a modest worst case and a realistic path to 20% a year no longer holds with enough margin for the risks above.