When Masayoshi Son committed SoftBank Group to investing up to $40 billion in OpenAI — the largest single investment in a private technology company in history — he wasn’t just making another audacious bet on the future of artificial intelligence. He was positioning himself, and his sprawling conglomerate, at the very center of what he believes will be the most transformative technology shift in human history. But as details of the deal emerge, questions are mounting about how deeply intertwined Son’s personal financial interests are with SoftBank’s corporate strategy, and whether the governance structures around the investment adequately protect the Japanese conglomerate’s other shareholders.

According to reporting by The Information, the structure of SoftBank’s massive OpenAI investment is set to personally benefit Son in ways that extend well beyond his role as the company’s largest shareholder. The arrangement has drawn scrutiny from corporate governance observers who note that the deal’s architecture could funnel disproportionate returns to SoftBank’s chief executive, raising familiar concerns about the blurred lines between Son’s personal ambitions and his fiduciary obligations to SoftBank’s investors.

The Architecture of a Record-Breaking Deal

SoftBank’s commitment to OpenAI has unfolded in stages. The Japanese technology and investment giant initially participated in OpenAI’s $40 billion funding round announced in late March 2025, contributing a substantial portion of the capital. But the relationship deepened considerably with the announcement of a broader strategic partnership that would see SoftBank invest up to $40 billion total in the Sam Altman-led AI company, with the investment expected to close in tranches over the coming months. The deal values OpenAI at approximately $300 billion, a staggering figure that makes it the most valuable private company in the world.

The sheer scale of the commitment is remarkable even by Son’s standards — a man famous for his $45 billion bet on Uber, WeWork, and dozens of other startups through the original Vision Fund. But unlike those earlier investments, which were pooled across a diversified portfolio, the OpenAI wager represents a concentrated position that could define SoftBank’s financial trajectory for years to come. SoftBank has been restructuring its balance sheet and selling assets in part to fund its AI ambitions, signaling that Son views this moment as a once-in-a-generation opportunity.

How the Deal Benefits Son Personally

At the heart of the governance concerns is the way the investment is structured relative to Son’s personal economic interests in SoftBank. As The Information reported, the OpenAI bet stands to benefit Son as CEO in ways that go beyond the typical alignment of executive and shareholder interests. Son holds a significant personal stake in SoftBank — approximately 32% of the company’s shares — meaning he stands to gain enormously if the OpenAI investment appreciates in value and lifts SoftBank’s stock price or net asset value.

But the concerns go deeper than simple share appreciation. Corporate governance experts have noted that the decision-making process around the investment appeared to be driven overwhelmingly by Son himself, with limited independent oversight or pushback from SoftBank’s board. This pattern is consistent with Son’s historical management style — he has long operated SoftBank as an extension of his personal vision, making bold, conviction-driven bets that have sometimes paid off spectacularly (as with Alibaba) and sometimes resulted in catastrophic losses (as with WeWork). The OpenAI investment, by its sheer magnitude, amplifies both the potential upside and the governance risks.

Son’s AI Obsession and the Stargate Connection

The OpenAI investment cannot be understood in isolation. It is part of Son’s broader strategy to make SoftBank the dominant financial force behind artificial intelligence infrastructure. In January 2025, Son stood alongside President Donald Trump at the White House to announce the Stargate Project, a joint venture with OpenAI and Oracle aimed at investing up to $500 billion in AI data center infrastructure across the United States. SoftBank was named as the lead financial partner in the initiative, with Son pledging an initial $100 billion.

The Stargate announcement was a public relations coup for Son, who has cultivated a close relationship with Trump and positioned SoftBank as a key player in the administration’s push to maintain American dominance in AI. But it also raised questions about how SoftBank would fund such enormous commitments. The company’s balance sheet, while improved from its 2022 nadir, is not unlimited. Analysts at firms including Jefferies and Morgan Stanley have noted that SoftBank may need to raise additional capital — potentially through debt issuance or further asset sales — to meet its OpenAI and Stargate obligations without straining its financial position.

OpenAI’s Transformation and What SoftBank Is Really Buying

SoftBank’s investment also comes at a pivotal moment for OpenAI itself. The company is in the process of converting from its unusual capped-profit structure — originally designed to ensure that artificial general intelligence would benefit humanity broadly — into a more conventional for-profit corporation. This restructuring, which has been the subject of intense legal and public debate, is expected to be completed by the end of 2025 and is a precondition for much of the outside investment the company has attracted.

The conversion has not been without controversy. OpenAI co-founder Elon Musk has waged a high-profile legal and public campaign against the restructuring, arguing that it betrays the company’s founding nonprofit mission. A California judge in early 2025 declined to block the conversion but signaled that the courts would continue to scrutinize the process. For SoftBank, the restructuring is essential — it transforms OpenAI from an entity with structural limits on investor returns into a company where equity holders can capture the full upside of what may become the most valuable technology platform since the internet.

Governance Red Flags and Historical Parallels

The governance dynamics surrounding SoftBank’s OpenAI investment echo earlier episodes in the company’s history. During the Vision Fund era, Son made enormous, rapid-fire investment decisions — including the fateful bet on WeWork — with minimal independent board scrutiny. The resulting losses, which totaled tens of billions of dollars, led to a painful period of restructuring and soul-searching at SoftBank. Son acknowledged mistakes and pledged greater discipline.

Yet the OpenAI deal suggests that the fundamental dynamic has not changed. Son remains the dominant decision-maker at SoftBank, and his personal conviction about AI’s transformative potential appears to override traditional risk management considerations. As The Information detailed, the structure of the deal is designed in a way that aligns closely with Son’s personal financial interests, raising the question of whether independent directors and minority shareholders have sufficient voice in decisions of this magnitude.

The Competitive Stakes in the AI Arms Race

From a strategic perspective, Son’s logic is not difficult to follow. The race to build and deploy advanced AI systems is accelerating at a breathtaking pace, with enormous capital requirements creating natural barriers to entry. OpenAI, despite growing competition from rivals including Anthropic, Google DeepMind, and Meta’s AI division, remains the most recognized and commercially advanced AI company in the world. Its ChatGPT product has become synonymous with generative AI, and its enterprise and API businesses are growing rapidly.

By securing a massive equity stake in OpenAI and anchoring the Stargate infrastructure initiative, Son is betting that the winner-take-most dynamics that characterized earlier technology platform shifts — from mainframes to PCs, from PCs to mobile — will repeat themselves in AI. If OpenAI emerges as the dominant platform, SoftBank’s investment could generate returns that dwarf even the legendary Alibaba trade, which turned a $20 million bet into a gain of more than $70 billion. If, on the other hand, AI development proves more distributed, or if OpenAI stumbles technically or commercially, SoftBank could face losses that would make the WeWork debacle look modest by comparison.

What Comes Next for SoftBank and Its Shareholders

For SoftBank’s shareholders, the coming months will be critical. The company’s stock has been volatile, reflecting both enthusiasm about its AI positioning and anxiety about the concentration risk inherent in the OpenAI bet. Analysts are watching closely to see how SoftBank funds its commitments, whether additional governance safeguards are put in place, and how the Stargate Project progresses from announcement to execution.

Son, now 67 years old, has spoken publicly about his belief that artificial general intelligence — machines capable of matching or exceeding human cognitive abilities across all domains — could arrive within the next few years. He has described this as the reason he was born, framing his entire career as a prelude to this moment. It is a vision of extraordinary ambition, and the OpenAI investment is its most concrete expression. Whether it proves to be the masterstroke of a visionary or the overreach of a man who has confused personal conviction with corporate strategy will likely be debated for years to come. For now, Masayoshi Son has placed the biggest chip of his career on the table — and the world is watching to see where it lands.