SoftBank Group Corp. tumbled to a loss in the December quarter, weighed down by a drop in the value of the Vision Fund’s public holdings, just as Masayoshi Son campaigns to raise $500 billion for the Stargate artificial-intelligence project.

By Anton Bridge TOKYO (Reuters) -Japanese technology investor SoftBank Group booked a surprising net loss of 369.2 billion yen ($2.4 billion) in the October-December quarter as valuations at its Vision Fund investment arm fell.