A2 Milk stock slumps 20% as margin outlook disappoints investors; Synlait falls

A2 Milk stock slumps 20% as margin outlook disappoints investors; Synlait falls
Paul McBeth
By Paul McBeth May 16 (BusinessDesk) - A2 Milk Co shares shed about a fifth of their value after a trading update today disappointed investors optimistic about the milk marketing firm's outlook, dragging down production partner Synlait Milk and weighing on the broader market.  Shares of A2 fell 20 percent to $10.45 after the Auckland-based company said second-half gross margin will stay broadly in line with the first half and expansion plans in the US and China underpin higher marketing costs. Synlait, which processes infant formula for A...