SoftBank's Funding Juggernaut Rolls On as SB Energy Files for a U.S. Listing

SoftBank filed for a US IPO of SB Energy and upsized an Arm-backed margin loan to $25 billion, as CDS costs hit a three-year high.

SoftBank Group is pressing ahead on two fronts at once: deepening its reliance on secured borrowing against its crown-jewel holdings, and steering a power-infrastructure subsidiary toward the public markets. The twin moves paint a picture of a conglomerate determined to keep its artificial-intelligence ambitions fully funded without parting with the assets underpinning them.

On the equity side, SB Energy — the SoftBank subsidiary focused on data centers and electricity infrastructure — has filed the paperwork for a U.S. initial public offering, according to a Reuters report. The company posted a 66.4% revenue jump in the first half of 2026, and the listing is set to involve the issuance of new shares worth up to $500 million to Japanese investors. The business sits squarely in a segment under heavy strain from the global buildout of computing capacity, where reliable power supply and specialized sites are increasingly seen as make-or-break factors for advancing modern technology. For the parent, the float offers a way to establish a market valuation for the unit while adding financial flexibility for future tech projects.

That flexibility is clearly in demand. Bloomberg reports SoftBank has upsized a margin loan backed by its stake in chip designer Arm to $25 billion, extending a pattern of pledging core holdings as collateral to raise fresh capital for large-scale AI bets rather than selling shares outright. Talks are also underway with Apollo Global Management to lift an existing credit line secured by Vision Fund 2 assets from $5.4 billion to as much as $9 billion, though no final figure has been locked in.

The borrowing spree accompanies hefty capital commitments. SoftBank has pledged a total of $64.6 billion to OpenAI, and in August 2026 it closed a $10 billion margin loan backed by its OpenAI stake, with Apollo participating as a lender. The company has also retired early the entire outstanding balance of a $25.9 billion bridge facility, raised primarily to fund follow-on investments in the U.S. firm.

Not everyone is cheering. The cost of insuring against a SoftBank default via credit default swaps has climbed to a three-year high, and a possible high-yield bond issue of $10 billion to $20 billion is under discussion. On September 4, Bloomberg reported, the group priced a retail bond of ¥1 trillion with a 4.75% coupon, and management traveled to New York roughly a week earlier to gauge demand for a dollar-denominated high-yield sale.

The market's reaction has been volatile. Monday brought an 11% slide to €35.01 after Bloomberg flagged a possible delay to OpenAI's IPO beyond 2026, with investors questioning the group's heavy concentration in AI. By Thursday the stock had rebounded 6.6% to €36.80, helped by the SB Energy plans and progress on refinancing. With a market value of roughly €185.65 billion, SoftBank's fortunes remain tightly bound to how its technology bets mature — and to whether its increasingly leveraged financing structure can keep carrying them.