⚠ A Few Customers Wield Real PowerHigh threat

Co-dependence is mutual, and the 'mutual' part is a genuine vulnerability: with only a handful of leading-edge customers, ASML's fortunes are hostage to the health and decisions of a very few firms. If one of the three giants falters — as Intel's foundry ambitions have repeatedly struggled¹ — or slows its leading-edge investment, or consolidates, or drives an unusually hard bargain, the impact on ASML is large and direct, because there is no broad base of customers to cushion it. Extreme customer concentration means each major buyer's problems become ASML's problems.

The concentration also hands those few customers real negotiating power despite their dependence. TSMC in particular, as by far the largest and most advanced customer, is a partner ASML cannot afford to alienate, and a buyer of that scale extracts favorable terms even from a monopolist. And the customers' own cyclicality — their capex swings, their competitive battles, their exposure to end-markets like phones and AI — transmits directly to ASML with amplified force. The co-dependence is real and mostly protective, but it concentrates ASML's destiny in the hands of two or three companies whose stumbles, slowdowns, and hard bargaining it must absorb. A monopoly on the supply side is paired with an oligopsony on the demand side, and that balance is not entirely in ASML's favor.