SoftBank's 37% stake in Coupang, which sources have said was acquired for about $3 billion, was worth around $30 billion at the end of the March quarter. Coupang shares have slipped 14% since March.
Gain on Coupang and investments like Uber Technologies are seen delivering a third quarter of growing profit for the fund, which pushed the group to a record loss last year as valuations fell during the onset of the COVID-19 pandemic.
In response to media reports that SoftBank's profit is to set a domestic record, the conglomerate said it would record gains but valuations were still being calculated.
Other big bets by Chief Executive Masayoshi Son, including ride-hailing firms Grab and Didi, are also heading to public markets although analysts warn returns may not match the supersized Coupang gain.
"Upside for SoftBank is not as high as it was with those earlier investments," said Kirk Boodry, an analyst at Redex Research, who sees the Vision Fund unit posting about $30 billion in quarterly gain.
The expected profit helps obscure Vision Fund missteps including investment in collapsed supply chain financier Greensill, and comes as companies like hotel chain Oyo grapple with a pandemic-induced downturn.
SoftBank's gains are mostly unrealised and some observers see Grab's record $40 billion merger with a blank-cheque company marking a peak for the investment vehicles amid concern over rich valuations for tech firms.
(Reporting by Sam Nussey; Editing by Tom Hogue and Stephen Coates)
By Sam Nussey