As OpenAI exposure surges and debt climbs, investors are asking whether SoftBank is building the future—or replaying WeWork on a much larger scale.
MARKET INSIDER – Few companies embody the artificial intelligence boom more dramatically than Japan’s technology investment powerhouse SoftBank. But as investors celebrate the company’s meteoric rise to become Japan’s most valuable listed firm, a growing number of analysts are warning that beneath the AI euphoria lies a potentially dangerous reality: a highly leveraged bet on a single transformative technology and one company at its center—OpenAI.
The stakes extend far beyond Japan. SoftBank’s aggressive financing strategy has become a global test case for how much risk investors are willing to tolerate in pursuit of AI-driven returns. If OpenAI continues its extraordinary ascent, SoftBank could cement its place as one of the biggest winners of the AI era. If not, concerns about liquidity, debt sustainability, and concentration risk could quickly move from theoretical to urgent.
SoftBank shares have surged roughly 70% this year, fueled by soaring valuations across the AI ecosystem. The rally has been supported by the strong performance of chip designer Arm Holdings and growing expectations that OpenAI could eventually deliver one of the largest technology IPOs in history. The market enthusiasm has been powerful enough to propel SoftBank past Toyota Motor Corporation in market capitalization, marking a remarkable turnaround from the years following its disastrous investment in WeWork, which ultimately cost the group more than $14 billion.
Yet analysts argue that the market may be overlooking a rapidly growing imbalance between opportunity and risk. SoftBank secured a $40 billion bridge loan earlier this year to finance additional OpenAI investments and other corporate needs. By the end of 2025, the company’s stand-alone interest-bearing debt had reached approximately ¥16.3 trillion, or about $104 billion. At the same time, ratings agencies estimate that OpenAI now accounts for roughly 30% of SoftBank’s investment portfolio—placing it alongside Arm as one of the conglomerate’s most critical assets.
That concentration is precisely what worries skeptics. S&P Global Ratings downgraded SoftBank’s outlook to negative earlier this year, citing concerns that the company’s liquidity profile, portfolio quality, and financial flexibility could deteriorate as a result of its expanding OpenAI exposure. Analysts note that the company’s future valuation is becoming increasingly tied to one assumption: that OpenAI’s growth trajectory and eventual public-market debut justify today’s extraordinary expectations.
The parallels with past technology cycles are difficult to ignore. SoftBank’s founder, Masayoshi Son, has built a reputation on making bold, concentrated bets on transformative technologies. His early investment in Alibaba Group became one of the most successful venture investments ever made. But his conviction in WeWork became one of Silicon Valley’s most expensive cautionary tales. Critics argue that OpenAI represents another high-conviction wager—albeit on a company with significantly stronger fundamentals and strategic importance.
Supporters counter that SoftBank’s balance sheet remains far healthier than headlines suggest. The company continues to hold substantial liquid assets, while its loan-to-value ratio remains below 25%, a level many investors consider manageable. From this perspective, even a disappointing OpenAI outcome would likely result in portfolio markdowns rather than an existential solvency crisis. Lenders also remain willing to extend financing against SoftBank’s vast equity holdings, providing an important buffer against short-term shocks.
For Son, however, the debate misses the bigger picture. He has repeatedly argued that artificial intelligence represents a technological revolution many times larger than the internet boom of the late 1990s. In his view, any future correction in AI-related assets would not signal failure but rather create the next generation’s greatest investment opportunity.
The broader question for global investors is whether the AI boom is entering a new phase—one where execution matters more than vision. SoftBank’s future may ultimately depend less on how much AI transforms the world and more on whether OpenAI can deliver the growth, profitability, and eventual public-market valuation that today’s optimism already assumes. If it succeeds, SoftBank could become the defining investment vehicle of the AI era. If it falls short, investors may discover that leverage amplifies disappointment just as effectively as it magnifies success.
