LME Zinc is looking vulnerable to a technical selloff with prices having been "rescued" at the last minute Thursday, a trader says. "This can't keep happening (to zinc) - it's very weak and I think today will be the determining point for prices," he adds. The 200-day moving average is the key technical support, located around $3,600/ton. LME zinc trades at $3,605/ton, down 2% from Thursday's high.