ASML Holding NV's stock fell sharply by 5.08% during intraday trading on Wednesday, as investors reacted to reports of China's progress in developing its own extreme ultraviolet (EUV) lithography machine.

The decline follows an exclusive Reuters report revealing that Chinese scientists, including former ASML engineers, have built a working prototype of an EUV machine. This development could challenge ASML's monopoly in advanced semiconductor manufacturing equipment, a key driver of its valuation.

While the Chinese prototype is not yet producing commercial chips, its existence suggests China may be closer to semiconductor self-sufficiency than previously anticipated, potentially reducing long-term demand for ASML's machines in the Chinese market.