SoftBank Group is reportedly preparing to issue over $11 billion in bonds, a move that would rank among the largest high-yield debt offerings ever executed, according to sources familiar with the matter on Monday. The Japanese conglomerate, led by billionaire Masayoshi Son, is simultaneously intensifying its financial commitment to OpenAI, the developer behind ChatGPT.

The planned issuance includes $10 billion in dollar-denominated bonds spread across three tranches, alongside €1 billion (approximately $1.1 billion) in euro-denominated notes split into two segments. A portion of these proceeds is earmarked for the next round of investment in OpenAI, which is expected to close next month, with pricing potentially set as early as Thursday.

As one of the largest AI investors globally, SoftBank's trajectory is increasingly tied to its ability to monetize its stake in the San Francisco-based startup. The group has already pledged nearly $65 billion to the technology pioneer, placing Masayoshi Son at the forefront of a debt-fueled AI investment wave, even as concerns over AI safety continue to mount.

A Surge in Debt-Financed Investments

SoftBank finalized a $40 billion bridge loan in March to fund additional investments in OpenAI, and recently settled the outstanding $25.9 billion balance of that facility. The company has been aggressively tapping debt markets to build out its AI financing capabilities, executing a series of borrowing maneuvers in recent weeks.

As of last weekend, the group's potential new borrowing had reached nearly $21 billion. Sources indicated on Friday that SoftBank had expanded a margin loan backed by shares of its semiconductor unit Arm Holdings (ASX: ARM) by $5 billion, bringing the total to $25 billion. Additionally, the firm secured an extra $450 million under its existing credit lines, pushing that facility to $6.5 billion.

Reports also suggest that Apollo Global Management is in discussions with SoftBank to increase a loan from $5.4 billion to $9 billion, aimed at bolstering its OpenAI commitments. Another $11.87 billion loan has been obtained by SoftBank, also designated for the OpenAI investment push.

Data shows SoftBank has already issued nearly $15 billion in bonds across various currencies this year, making it the largest high-yield borrower in the bond market for 2026 to date. Earlier this year, the group also secured a $10 billion loan collateralized by its OpenAI holdings.

Higher Borrowing Costs Amid AI Safety Concerns

These transactions are unfolding against a backdrop of rising borrowing costs across global markets, as major economies grapple with inflation. Yields on SoftBank's dollar bonds maturing in 2031 climbed to 8.2% earlier this month, up from a January low of 6.7%, driven by widening credit spreads and rising U.S. Treasury yields.

Adding to the uncertainty, leaders at AI giants including OpenAI have recently called for a slowdown in AI development, citing safety concerns. This has not only clouded the outlook for AI-related deals but has also intensified scrutiny on SoftBank's deep bet on the ChatGPT maker. Consequently, the cost of insuring SoftBank's debt against default has risen to its highest level in three years.

OpenAI CEO Sam Altman recently noted that the much-anticipated initial public offering remains in the pipeline but will not occur this year as some investors had hoped. This development is closely watched by investors, as a listing was expected to enhance the liquidity of SoftBank's stake in the company.

If the approximately $11 billion bond issue proceeds, it would rank among the largest high-yield offerings ever made by a single company, excluding distressed debt exchanges. S&P Global Ratings currently assigns SoftBank a BB+ rating, its highest speculative-grade designation. By comparison, two of 2026's largest corporate issuers, Alphabet and Amazon, hold ratings of AA+ and AA respectively, both above Japan's sovereign rating.