A $60 billion bet on OpenAI has turned SoftBank into a pure-play AI stock, and markets are pricing in every twist accordingly
SoftBank has spent the better part of 2026 riding the OpenAI hype cycle. In May, shares surged nearly 20% in a single session when reports surfaced that OpenAI was preparing to file for its IPO. Then came the drop: shares fell as much as 11% in early June as concerns about high leverage, stalled financing, and increased competition for IPOs began circulating.
How SoftBank became OpenAI’s shadow stock #
SoftBank’s cumulative investment in OpenAI now exceeds $60 billion, with the firm targeting an ownership stake somewhere between 11% and 13%.
OpenAI filed a confidential S-1 with the SEC on June 8, 2026, a procedural step that allows companies to go through initial SEC review before making their filings public. The filing pointed to a potential valuation exceeding $850 billion. But executives signaled that the timeline could still stretch further out, noting the strategic advantages of remaining private and flagging readiness concerns.
Leverage, credit downgrades, and a stalled loan #
S&P Global Ratings downgraded SoftBank’s credit outlook to negative in March 2026, citing the concentrated risk embedded in its OpenAI position.
Around June 10, 2026, SoftBank shares saw an additional drop of roughly 8% to 9.7% linked to a stalled $6 billion margin loan. A margin loan is a loan secured by the value of an investment. If the investment’s value wobbles, the loan terms get uncomfortable fast.
Masayoshi Son, the firm’s founder and chief executive, has a well-documented history of concentrating enormous capital into single high-conviction bets. The OpenAI position is the largest single bet the firm has ever made.
What this means for investors watching from the sidelines #
Reports of stalled financing and rival IPO competition emerged in early June as context for the initial drop, suggesting that the market is beginning to apply more scrutiny to AI-adjacent valuations.
The stock’s wild swings in both directions this year — up nearly 20% in a day, down 11% a few weeks later, down another 8% to 9.7% around June 10 — reflect what concentrated tech exposure looks like in practice.
For traders watching the AI IPO space, the key variable to track is the timeline. Every week the IPO stays on the horizon rather than on the calendar is another week SoftBank’s leveraged position is exposed to sentiment shifts. Disclosure: This article was edited by Editorial Team. For more information on how we create and review content, see our