SoftBank Group Corp. is planning to cut at least 20% of staff at its loss-churning Vision Fund operation following public pledges from Masayoshi Son to reduce headcount at the world’s biggest tech investor, according to people familiar with the matter.

The Tokyo-based company will slash a minimum of 100 positions and may announce the job cuts as early as this month, said the people, asking not to be named as the information is not public. The cuts will mostly be at its U.K., U.S. and China operations, which have the largest headcount, said the people. The Vision Fund unit had about 500 employees, including Latin America funds staff.

Son, the self-made billionaire founder of the group, had said in August he plans widespread cost-cutting at his conglomerate and the Vision Fund investment arm after a record $23 billion loss. Most of the losses came from a plunge in the valuations of portfolio companies, including South Korea Coupang Inc. and DoorDash Inc. SoftBank also reported a $6 billion foreign exchange loss because of the weaker yen.