Europe's biggest tech giant slides 5% on reports of a Chinese rival encroaching on its turf

ASML CEO Christophe Fouquet with a Lego model of the company's EUV machine. Bloomberg/Getty Images ASML shares fell nearly 5% in premarket trading after reports that China had made a major chipbuilding breakthrough. Multiple outlets reported that a Chinese company had begun mass production of DUV lithography machines. ASML is the only company capable of building DUV machines at scale. China has been trying to catch up for years. Europe's most valuable company faces a new threat after China…