ASML Holding N.V. - New York Registry Shares (ASML) are New York registry shares of ASML Holding N.V., the leading supplier of lithography systems used in semiconductor manufacturing. ASML holds about 90% of the lithography-equipment market. Lithography uses light to project circuit patterns from a photomask onto a semiconductor wafer, allowing chipmakers to place more transistors on the same area of silicon. ASML outsources production of most components and focuses on system design, integration, and assembly. Its largest customers include TSMC, Samsung, Intel, SK Hynix, and Micron.