Shares of ASML Holding (NYSE:ASML) declined on Tuesday as investors reacted to a new legislative proposal from U.S. lawmakers that could significantly tighten restrictions on the company’s ability to sell and service advanced chipmaking equipment in China.
The proposed law, introduced last week, seeks to block the sale and ongoing maintenance of Deep Ultraviolet (DUV) immersion lithography tools to Chinese customers.
If enacted by the U.S. and subsequently enforced by the Netherlands, the bill would represent the first major expansion of export controls against the Dutch semiconductor equipment giant since September 2024.
In Amsterdam trading, ASML shares fell by as much as 4.7% before stabilizing at 1,114 euros, a 4.1% decrease by 11:00 GMT.
While ASML declined to comment on the legislative move, the Dutch government stated it would not comment on specific proposals currently moving through the U.S. legislature.
ASML currently holds a dominant position in the global market for lithography tools, which are essential for printing the intricate circuitry of modern semiconductors.
While the company faces competition from Japan’s Nikon and the Chinese state-backed SMEE, its high-end immersion DUV systems remain a critical bottleneck for Chinese chipmakers attempting to scale production of advanced nodes.
The financial implications of the proposed restrictions remain a point of debate among market observers. A
SML has previously forecast that China would account for approximately 20% of its total sales in 2026.
Because the bill specifically targets DUV immersion technology, sales of older, less sophisticated "dry" lithography machines would likely remain unaffected.