SoftBank's $3.9 Billion Short Bet Is Fueling the Rally It Was Meant to Fade

SoftBank shares jump 23% in seven sessions as record short interest unwinds, with a dollar junk-bond roadshow set for September 14-17.

SoftBank Group has spent the past seven days proving an uncomfortable truth about crowded trades: betting against a stock can be the very thing that lifts it. Shares of the Japanese conglomerate closed Thursday at EUR 36.70 and were changing hands at EUR 37.47 on Friday, a gain of 2.1% on the day. Zoom out, and the move looks even sharper — up 23% over seven sessions and 22% across 30 days, a run that has left short sellers scrambling and handed the bulls a market capitalization of roughly EUR 209.09 billion.

The fuel behind that climb is partly mechanical. According to Bloomberg, short interest as a share of SoftBank's free float reached 2.27% by Wednesday, the highest reading since July 2025. In nominal terms, those bearish positions totaled USD 3.9 billion — a record at least since early 2015. Bloomberg speculates that a forced unwind of those bets could drive the stock even higher, a scenario in which the skeptics who were most convinced of a pullback end up supplying the momentum for the opposite move.

A Balance Sheet Built on Borrowed Conviction

None of this happens in a vacuum. SoftBank has wagered tens of billions on artificial intelligence, levering its balance sheet to do so. A USD 40 billion bridge facility taken out this year helped fund investments tied to OpenAI, and the group is now hunting for longer-term replacement capital. The urgency is concrete: on September 15, SoftBank intends to repay the entire USD 25.9 billion outstanding under that bridge — the amount originally drawn from the larger facility — retiring the short-term obligation ahead of schedule.

The next test arrives almost immediately. CFO Yoshimitsu Goto and other executives will meet investors at Citigroup's offices from September 14 to 17, gauging appetite for a dollar-denominated junk bond. Media reports suggest the group could raise between USD 10 billion and USD 20 billion, potentially with a euro tranche attached. The roadshow follows last week's pricing of a retail bond worth JPY 1 trillion — about USD 6.3 billion — at the top of its targeted range with a 4.75% coupon. Part of those proceeds will refinance existing debt, while another slice funds the acquisition of ABB's robotics unit.

The coupon itself tells a story. SoftBank carries a BB+ rating from S&P Global Ratings — the highest rung of speculative grade, but speculative nonetheless. Japanese media have drawn the contrast with Alphabet at AA+ and Amazon at AA, a gap of several notches between SoftBank and the tech heavyweights it competes against in the AI race. That spread is precisely what the group is trying to bridge with fresh borrowings.

The Math That Worries Creditors

Bloomberg Intelligence analyst Sharon Chen has laid out the arithmetic: gross debt could climb from roughly USD 80 billion in March 2025 to more than USD 130 billion if SoftBank funds its pipeline through additional borrowing. Not every corner of the portfolio is pulling its weight. Subsidiary SB Energy posted a half-year loss of USD 3.2 billion on revenue of just USD 139 million — a discrepancy that could give US investors pause when weighing the group's creditworthiness.

Whether New York buyers reward SoftBank's AI thesis or demand a steeper risk premium will shape how easily — and how expensively — the conglomerate raises future debt. A successful placement would lock in refinancing for the OpenAI bridge and other commitments without straining the balance sheet unduly, recasting the September 15 repayment as a display of financial discipline rather than a stopgap measure. A tepid reception would force the group to either pay up or scale back the offering, feeding doubts about whether its multi-billion-dollar AI bets can be sustained by cash flow or only by successive rounds of new debt.

Reading the Technicals

The charts offer little comfort to either camp. An RSI of 71.2 — or 70.6, depending on the reading — flags an overbought condition, while annualized volatility of 62% (61% on another measure) captures just how jittery the market's pricing of SoftBank has become. The recent rally, propelled by a broad AI trade across Asia, reflects sentiment rather than fundamental confirmation, and could reverse quickly on disappointing news from New York.

If the investor meetings through Thursday signal broad confidence in SoftBank's credit quality, the group should be able to execute its refinancing plan as laid out: retire the bridge loan on September 15, then follow with a dollar bond. Should sentiment sour — if investors weight the SB Energy losses more heavily than the AI narrative — costlier terms or a smaller issue size become likely. The roadshow's close on September 17, followed by the eventual pricing of any dollar bond, now stands as the clearest signpost for where SoftBank heads next.