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ASML (ASML) — moat facet
A monopoly with almost no customers — one buyer is 23.9% of sales, two are 38%, and roughly five organisations on earth can use the flagship machine.
ASML's customer concentration is the most extreme in this collection, and it is getting worse. Sales to its largest customer were €7,796.7 million, or 23.9% of total net sales in 2025, against €4,682.4 million and 16.6% in 2024. The two largest customers together were 38.0% of net sales in 20251.
The filing puts it plainly: while the ranking of the largest customers may shift year to year, sales remain concentrated among a limited group, and the loss of any key customer or a substantial change in purchasing behaviour could materially affect the business.
The structural reason is simple arithmetic. Only three companies in the world manufacture logic at the leading edge, and only they can use an EUV machine. Add the leading memory makers and the entire addressable customer base for ASML's most important product is perhaps five organisations. A company can be a monopoly and still have almost no customers — ASML is both at once, and the two facts roughly offset.
What makes the relationship workable is that the dependence runs harder in the other direction. A customer that stops buying ASML tools stops advancing, which in this industry means it stops existing at the leading edge. That is why the concentration has never yet cost ASML anything, and why the number worth watching is not the concentration itself but the customers' capital spending — the one variable neither ASML nor its monopoly controls.
Concentration deepened materially: the largest customer went from 16.6% to 23.9% of sales in a single year and the top two reached 38%. The leading edge is consolidating into fewer, larger buyers, which is good for ASML's pricing and worse for its risk. The offset — that customers depend on ASML more than it depends on any of them — is intact and is why this has never yet cost anything.
The largest alone was 23.9%, up from 16.6% a year earlier. Only about five organisations on earth can use an EUV machine, so ASML is simultaneously a monopoly and a company with almost no customers. Watch customers' capital spending plans, which are published a year ahead.
Source: ASML Form 20-F, FY2025 ↗- ReportedThe largest customer was EUR 7,796.7M or 23.9% of net sales in 2025 (from 16.6%), and the two largest were 38.0%; ASML warns the loss of any key customer could materially affect the business.ASML Form 20-F, FY2025 — total net sales to the largest customer amounted to EUR 7,796.7 million, or 23.9% of total net sales in 2025, compared with EUR 4,682.4 million, or 16.6%, in 2024; in 2025, 38.0% of total net sales were made to the two largest customers; while the ranking of the largest customers may shift year to year, sales remain concentrated among a limited group, and the loss of any key customer or a substantial change in their purchasing behaviour could have a material adverse effect; metrology and inspection customers largely overlap with those purchasing lithography systems — FY2025 (ended December 31, 2025) · publ. February 25, 2026 · source ↗