SoftBank Group Corp. is negotiating an additional investment of up to $30 billion in OpenAI, intensifying its aggressive push into artificial intelligence as the ChatGPT creator seeks as much as $100 billion in fresh capital. The potential deal, which could value OpenAI at around $830 billion, underscores Chief Executive Masayoshi Son’s “all-in” commitment to the startup amid soaring costs for AI development and intensifying rivalry from Alphabet Inc.’s Google. People familiar with the discussions described the talks as preliminary, with no final agreements reached.

This follows SoftBank’s completion of a $41 billion investment in OpenAI last December, securing an 11% stake through a combination of $7.5 billion initially, $22.5 billion later, and $11 billion from co-investors via its Vision Fund 2. To fund that prior commitment, SoftBank sold a $5.8 billion stake in Nvidia Corp., redirecting resources toward what Mr. Son views as the premier player in generative AI. OpenAI neither confirmed nor denied the reports, while SoftBank declined to comment.

Prior Bets and Funding Momentum

The Japanese conglomerate’s deepening ties with OpenAI trace back to earlier 2025 rounds, including a $40 billion raise valuing the company at $300 billion post-money, where SoftBank led with commitments structured in tranches. OpenAI’s transition to a for-profit public benefit corporation earlier that year unlocked such massive inflows, resolving prior nonprofit equity restrictions. Microsoft Corp. remains the largest shareholder with about 28%, valued at $135 billion to $140 billion on recent secondary sales pegging OpenAI at $500 billion.

SoftBank’s Tokyo shares surged over 8% on the news before settling 3.4% higher at 4,190 yen, reflecting investor optimism. Tomoichiro Kubota, senior market analyst at Matsui Securities, noted the positive signal for near-term sentiment but cautioned on rivals like Anthropic and Google’s Gemini gaining ground. “The competitive environment is getting more severe,” Mr. Kubota said, per MarketScreener.

OpenAI’s capital needs stem from escalating expenses to train frontier models, with total funding now exceeding $64 billion. The startup grapples with compute demands as it scales infrastructure, including commitments under the $500 billion Stargate project—a joint venture with SoftBank and Oracle Corp. to build AI data centers deemed vital for U.S. supremacy over China in the technology race.

Strategic Imperatives Driving the Deal

Mr. Son’s strategy positions SoftBank as a pivotal force in AI, extending beyond OpenAI to ventures like a 50-50 Japan joint entity, SB OAI Japan, launched in November 2025 to localize enterprise AI solutions. “Together with OpenAI we’re driving the AI revolution to the next stage,” Mr. Son declared in November, per Mobile World Live. This aligns with SoftBank’s $100 billion U.S. investment pledge, including Stargate contributions separate from direct OpenAI equity.

The proposed $30 billion would represent nearly a third of OpenAI’s targeted round, cementing SoftBank’s influence as Sam Altman pursues diversification from Microsoft reliance. On X, analyst Andrew Curran highlighted SoftBank’s Nvidia divestment as evidence of conviction in OpenAI’s dominance: “SoftBank has sold their stake in NVIDIA and appears to believe that OpenAI is the best bet in the industry,” he posted, linking the Wall Street Journal report.

Discussions occur against OpenAI’s operational strains, including a $30 billion annual Oracle deal for 4.5 gigawatts of capacity—equivalent to two Hoover Dams—tied to Stargate. OpenAI CEO Sam Altman has voiced concerns over delivery timelines despite revenue growth, emphasizing infrastructure as key to sustaining leadership.

Market Reactions and Broader Ramifications

Reuters confirmed the talks, citing sources who detailed the $830 billion valuation scenario, with SoftBank eyeing enhanced positioning in the AI race (Reuters). The Asahi Shimbun emphasized Mr. Son’s scramble to fund the prior round, pausing Vision Fund activity. Benzinga reported SoftBank’s 11% holding post-$22.5 billion close, with shares reacting sharply (Benzinga).

Verdict noted the Stargate overlap, projecting $500 billion in data centers to bolster U.S. AI edge (Verdict). On X, reactions ranged from praise for OpenAI’s moat to skepticism on funding sources, with one user questioning: “Where are they even going to get the money?” amid SoftBank’s leveraged balance sheet.

For industry insiders, this signals a maturing AI investment paradigm: mega-rounds funding compute wars, with SoftBank leveraging syndication to amplify bets. OpenAI’s trajectory—from $157 billion in October 2025 to potential $830 billion—highlights valuation inflation, yet underscores the trillion-dollar stakes in AGI pursuits. As Mr. Son doubles down, the question lingers: Can OpenAI deliver returns justifying the frenzy?