Nine months after stock-market wagers on a baby boom in China reached record levels, the bets have turned into some of the nation’s biggest losers as living costs deter couples from having more than one child. While milk-powder producers Biostime International Holdings Ltd. (1112) and Yashili International Holdings Ltd. (1230) surged to all-time highs after the ruling Communist Party relaxed its one-child policy last November, the stocks have lost at least 40 percent this year, with Biostime leading declines in the MSCI China Index. Hengan International Group Co. (1044), a diaper maker, has dropped 8.4 percent even ... (full story)