⚠ The Law of Large NumbersModerate threat

Scale is a moat, but it is also a ceiling on growth. At roughly $139 billion in systemwide sales across a near-saturated developed-market footprint, McDonald's is so large that meaningful percentage growth is mathematically hard — the law of large numbers means each additional point of growth requires an enormous absolute increase in sales, and the easy expansion is behind the company in its richest markets. The result is a business that grows, reliably, at mid-single-digit rates rather than the double digits of a younger chain, and that is acutely sensitive to comparable-sales trends because new units alone cannot move the needle much.

The recent results make the vulnerability concrete: global comparable sales grew just 1.3% in the second quarter of 2026, down from 3.8% a year earlier¹, as a pressured consumer pulled back — and at McDonald's scale, a soft comp quarter is felt across an enormous base. Scale does not protect against a weak consumer; if anything, it means the company rises and falls with the broad health of the mass-market diner. This is not a threat to the moat — a company this large has already won its market — but it is a permanent constraint on the growth rate, and a reminder that McDonald's is a mature compounder whose sheer size makes rapid acceleration difficult and whose results track the consumer closely.