ASML stock dropped to its lowest since June after a Chinese consortium began producing homegrown DUV lithography machines, raising concerns about

A Shanghai-based company has begun making immersion DUV lithography machines, The Information reported. ASML shares dropped 6.5%. China's share of ASML sales fell to 14%.

ASML stock tumbled on a report of competition emerging in China. It was among the biggest losers on the Philadelphia semiconductor index.

On the one hand, US controls on exports of high-tech goods to China are threatening to reduce access to a major market; and on the other, Beijing's push for technological…