SoftBank Group issued $11.1 billion in dollar- and euro-denominated bonds on September 24, the largest high-yield corporate bond sale in history. The proceeds fund its stake in OpenAI. Shares rose 7 percent in Tokyo on announcement. Masayoshi Son is borrowing at scale to place a single bet.
The issuance splits between dollar and euro tranches, both priced at high-yield levels reflecting SoftBank's BB credit rating. This surpasses the prior high-yield record and ranks among the top ten corporate bond sales of any grade globally. The timing follows SoftBank's September commitment to participate in OpenAI's $6.6 billion funding round at a $157 billion valuation. Son has called artificial general intelligence the defining investment of the decade. He is deploying balance sheet leverage to match that conviction.
The market absorbed the paper without hesitation, signaling continued appetite for technology exposure through credit. SoftBank's debt-to-equity ratio already exceeds 1.4x after Vision Fund writedowns and the Arm Holdings IPO proceeds. This issuance pushes gross debt above $85 billion, with $28 billion in cash and liquid holdings against it. The net debt position tightens to roughly $57 billion, leaving minimal cushion for mark-to-market volatility in the Vision Fund or Arm share price. Son has historically operated near the edge of prudent leverage; this issuance puts him closer to the edge than at any point since the Alibaba margin loan episode in 2020.
The OpenAI bet itself carries execution risk distinct from SoftBank's prior technology wagers. OpenAI's revenue model remains subscriptions and API access, with gross margins in the 60 percent range but burn rates still above $5 billion annually. The $157 billion valuation implies a path to $15 billion in revenue within three years at current SaaS multiples. SoftBank is underwriting a scaling trajectory that requires enterprise adoption, continued model leadership, and regulatory clearance across jurisdictions. If any of those assumptions compress, the valuation compresses with them, and SoftBank holds illiquid paper funded with very liquid bond obligations.
Watch for SoftBank's quarterly disclosure in November, which will detail the OpenAI stake size and accounting treatment. Vision Fund performance reporting in the same period will clarify whether other portfolio exits are planned to reduce net debt or whether Son intends to hold leverage at these levels through the AGI cycle. Credit spreads on the new bonds will trade independently and offer a real-time gauge of market conviction in Son's thesis. The euro tranche particularly bears watching; European institutional buyers of high-yield tech credit have been more sensitive to duration risk than their U.S. counterparts.
SoftBank now holds OpenAI exposure funded by the largest high-yield bond sale in history, with a stock price that moved 7 percent on the news and a balance sheet offering no room for error. The next twelve months will clarify whether Son timed the intelligence revolution or simply refinanced into it.