News that Alibaba co-founders Jack Ma and galeri klip lucahJoe Tsai bought $200 million worth of shares in the Chinese e-commerce giant in the fourth quarter sent the firm’s New York-listed stock up nearly 8% on Tuesday. A report in the New York Times said Ma bought $50 million in Hong Kong shares in Alibaba during the quarter, while current chairman Tsai purchased $151 million worth of its US-traded stock via his Blue Pool Management family investment vehicle, showing their support for the 25-year-old firm as it faces multiple challenges. The company’s Hong Kong-traded shares rose 4.3% in the exchange’s Wednesday morning session. Ma believes Alibaba stock is now “strongly below its actual value,” the firm’s chief people officer Jane Jiang told employees in November, confirming that the company’s founder had postponed his plan to sell 10 million shares at a value of around $870 million. [The New York Times; SEC filling]