AutoZone (AutoZone (AZO)) reported better-than-expected third-quarter earnings on Tuesday, but you wouldn't know it from the stock's performance. Shares dropped more than 10% to a new 52-week low, a reminder that even good news can get punished in a nervous market.

The automotive-parts retailer posted earnings of $38.07 per share, beating the analyst consensus of $36.10. Revenue came in at $4.84 billion, up 8.4% from a year ago and slightly ahead of the $4.83 billion Wall Street had expected. So what gives?

Part of the answer might be in the details. Gross margin slipped 57 basis points to 52.2%, partly due to a non-cash LIFO charge. Inventory swelled 10.8%, driven by inflation and growth initiatives. And while operating profit rose 6.6% to $923.8 million, net income increased to $641.5 million from $608.4 million — solid, but not enough to excite investors already jittery about consumer spending.

Still, the underlying business looks healthy. Same-store sales rose 5.5% overall, with domestic stores up 4.1% and international stores jumping 16.6% (or 1.6% on a constant-currency basis). The company opened 57 new stores in the U.S., 20 in Mexico, and five in Brazil during the quarter, for a total of 82 net new locations.

CEO Phil Daniele said it was AutoZone's strongest sales growth since fiscal 2023, driven by market-share gains, commercial demand, and new store openings. He noted that the company plans to open about 365 stores globally this year, up from 305 last year, while expanding its hub and megahub network to improve inventory availability and delivery speeds.

Domestic commercial sales rose 10.4%, reflecting gains with both national-account and local commercial customers. Daniele also pointed to long-term demand drivers: an aging vehicle fleet and a tough new- and used-car market that keeps people repairing their existing cars.

CFO Jamere Jackson added some color on the call, describing the auto-parts business as "pretty inelastic" because many repairs are unavoidable. He acknowledged that consumers might delay maintenance temporarily, but noted that deferred repairs often lead to larger and more expensive failures later, which helps support long-term demand stability. In other words, you can put off an oil change, but you can't put off a blown engine.

AutoZone expects to invest roughly $1.6 billion in capital expenditures this year and next, mainly in stores, hubs, megahubs, and technology upgrades. Jackson said the company sees significant long-term opportunity in the underpenetrated commercial auto-parts market, and that its megahub strategy continues to outperform internal expectations.

The company also repurchased 164,000 shares during the quarter at an average price of $3,582 per share, totaling $586.3 million. At quarter's end, it had $800 million remaining under its current buyback authorization. Cash and cash equivalents stood at $253.73 million, and operating cash flow rose to $847.39 million from $769.03 million a year earlier.

So why the stock drop? It's possible that investors were hoping for even stronger results, or that the margin compression spooked them. Or maybe it's just a case of a good company in a bad market. Either way, AutoZone's core thesis — that people will keep fixing their cars, no matter what — seems intact.