Alibaba’s co-founder Jack Ma (pictured) will leave SoftBank’s board after 13 years, as the troubled conglomerate posted a record $13bn (£10bn) operating loss.The heavy loss for the Japanese technology and telecoms business comes after a string of poor bets in its $100bn Vision Fund, which has backed high-profile businesses such as ride-hailing firm Uber, office rental company WeWork and Indian hotel chain Oyo.“Values of Uber, WeWork and its three affiliates decreased, and total fair value of other portfolio companies decreased significantly,” SoftBank wrote on Monday.SoftBank’s Vision Fund has backed 88 start-ups with a total of $75bn.Ma, whose $41.8bn net worth makes him China’s richest man, will depart his board seat at SoftBank on 25 June, the company said. Softbank board filled with insidersThe business did not offer a reason for Ma leaving, but did say the billionaire was increasingly interested in philanthropy.SoftBank’s founder, Masayoshi Son, was one of the first major investors in Alibaba, and his company’s holding of around 25% in the Chinese e-commerce giant is now worth over $100bn, making it SoftBank Group’s most valuable investment.The relationship between Ma and Son, two of Asia’s best-known tech tycoons, goes back over 20 years, when Son became one of the earliest investors in Alibaba.Softbank has proposed three new appointments to the board, largely composed of Softbank insiders, that would expand its strength to 13. These include Lip-Bu Tan, chief executive of chip design software firm Cadence Design Systems, Softbank’s Chief Financial Officer Yoshimoto Goto, and Yuko Kawamoto, a professor at Waseda Business School.The group board also includes Yasir al-Rumayyan, who heads the Saudi Arabian sovereign wealth fund that is the Vision Fund’s biggest outside backer.“Who is the voice of reason who can stand up to Son? You probably need more than one,” Nicholas Benes of The Board Director Training Institute of Japan told Reuters. “I am doubtful that these four outside directors, in a board of 13, will have much effect slowing Son down before the next WeWork deal.”Last month the group to announce plans to sell $41bn of its assets to raise cash and buy back $4.7bn of its shares.For more information on trading in Alibaba stock, please see our selection of some of the reputed online stock brokers for trading Alibaba. Alternatively, if you wish to trade derivatives, we also have reviewed a list of derivative brokers you can consider.