The investment firm has poured more than $30 billion into the ChatGPT maker since 2025, lifting its ownership stake to about 11%, and is in discussions to commit up to another $30 billion in OpenAI’s latest funding round, according to a Reuters report last month. The scale of that exposure has led analysts to view SoftBank as a publicly traded proxy for OpenAI, amplifying concerns over concentration risk and balance-sheet strain.
OpenAI has continued to strike multi-billion-dollar partnerships at rising valuations, even as it remains loss-making. That dynamic has unsettled some investors, who question how the company will fund its expanding infrastructure needs in an AI race where rivals such as Amazon and Google are spending well over $100 billion a year on capital expenditure.
SoftBank’s strategy reflects founder and Chief Executive Masayoshi Son’s long-standing preference for high-conviction bets on fast-growing but unprofitable companies. While OpenAI’s successive funding rounds have implied higher valuations, the gains remain largely notional for now.
Analysts estimate SoftBank will book an investment gain of about $4.45 billion from a $22.5 billion OpenAI tranche completed in December. Forecasts compiled by LSEG show quarterly net income expectations ranging widely, from a profit of 1.1 trillion yen ($7.07 billion) to a loss of 480 billion yen, underlining the volatility surrounding the group’s earnings.
SoftBank shares have been choppy, up roughly 2% so far in 2026 but down about 15% over the past three months, lagging major U.S. technology stocks as competition in the AI sector intensifies.
Attention is now turning to how SoftBank will fund further investments. The company has already sold some of its most liquid holdings to support its AI ambitions, including a $5.8 billion stake in Nvidia and part of its T-Mobile holding for $9.17 billion in the September quarter. At the same time, leverage has increased. Nomura estimates SoftBank’s loan-to-asset ratio may have risen to 21.5% at the end of December from 16.5% three months earlier.
Even if OpenAI achieves the roughly $830 billion valuation it is targeting in the current funding round, SoftBank’s leverage would only ease modestly, according to Nomura. Although the group’s long-term credit rating remains below investment grade at S&P, it retains some financial flexibility. In November it expanded the amount it can borrow against its Arm Holdings stake, with $11.5 billion still undrawn as of December, and it held about 3.5 trillion yen in cash and equivalents at the end of September.
Further asset monetisation and debt issuance are widely expected. External appetite for OpenAI exposure has so far been strong, with last year’s syndicated investment reportedly oversubscribed and companies such as Amazon and Nvidia in talks to join the latest round. Still, analysts caution that OpenAI’s once-clear lead is narrowing as rivals scale up, leaving SoftBank’s all-in wager increasingly tied to how the AI race ultimately plays out.