"We think today's weakness is an over-reaction and see current levels as an attractive opportunity."

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%.

Reports that China has started mass-producing homegrown DUV lithography machines actually describe two separate developments being treated as one. A Shanghai firm linked to…