Chinese-American billionaire investor Duan Yongping has increased his holdings in Pop Mart for a third time, reinforcing his long-term bullish view on the toy brand, as some questioned the sustainability of demand for the company’s intellectual property (IP) portfolio led by the blockbuster Labubu doll. Duan, 65, dubbed “China’s Warren Buffett” by some investors for his investment acumen, increased his stake in the Hong Kong-listed Pop Mart on July 6 through his wholly owned company H&H...