Jan 30 2021, 1:04 AM January 29 2021, 7:18 AM January 30 2021, 1:04 AM (Bloomberg) -- Up Fintech Holding Ltd. and Futu Holdings Ltd., two fast-growing online brokers that help Chinese investors invest overseas, will resume trading in GameStop Corp. and AMC Entertainment Holdings Inc. after briefly restricting transactions amid extreme volatility in the stocks. (Bloomberg) -- Up Fintech Holding Ltd. and Futu Holdings Ltd., two fast-growing online brokers that help Chinese investors invest overseas, will resume trading in GameStop Corp. and AMC Entertainment Holdings Inc. after briefly restricting transactions amid extreme volatility in the stocks. Up Fintech, better known as Tiger Brokers, will also resume trading in Koss Corp. on Friday and make every effort to fulfill customer needs through its clearing systems, it said in a statement. Futu said its upstream system had been restored.