Microsoft CEO Satya Nadella concluded his testimony in the high-profile Musk v. Altman trial, asserting that Elon Musk never directly voiced concerns about Microsoft’s multi-billion dollar investments in OpenAI to him. Musk accuses Microsoft of enabling OpenAI’s alleged breach of its charitable trust, a claim Nadella strongly refuted, emphasizing the clear commercial objectives of their long-standing partnership. The trial, which also featured testimony from OpenAI co-founder Ilya Sutskever, continues to unravel the complex relationship between these tech titans and the future of artificial intelligence governance.
Microsoft CEO Satya Nadella concluded his testimony on Monday in the highly anticipated Musk v. Altman trial, vehemently denying that Elon Musk ever directly communicated concerns to him regarding Microsoft's substantial investments in OpenAI. Nadella, dressed in a navy suit, spent several hours on the stand in Oakland, California, addressing questions about the early days of Microsoft's strategic partnership with OpenAI, his understanding of their relationship, and his role during the turbulent period when Sam Altman was briefly ousted as OpenAI's CEO.
Video: Microsoft CEO Satya Nadella testifies in OpenAI (3:17)
Musk, who co-founded OpenAI in 2015, initiated a lawsuit in 2024 against OpenAI, its CEO Sam Altman, and President Greg Brockman. He alleges they violated their foundational pledge to maintain OpenAI's non-profit structure and adhere to its charitable mission. Microsoft is named as a defendant, with Musk accusing the tech giant of aiding and abetting this purported breach of charitable trust.
Microsoft has been a pivotal supporter of OpenAI since 2019, long before ChatGPT's mainstream debut in late 2022. The company's investments, totaling over $13 billion (including $1 billion in 2019, $2 billion in 2021, and $10 billion in 2023), have been a central theme throughout the trial. Nadella expressed pride in Microsoft for taking the "risk" to invest in OpenAI when "no one else was willing."
Musk, who testified last month, pinpointed Microsoft's $10 billion investment as the "key tipping point" that led him to believe OpenAI was abandoning its non-profit roots. He stated that the sheer scale of the investment prompted a legal investigation, driven by concerns that "they were really trying to steal the charity."
Nadella countered this, asserting that Microsoft's investments were never considered donations, and a clear commercial aspect defined their partnership from its inception. He explained that Microsoft offered OpenAI significant discounts on computing resources in its early years, expecting marketing benefits in return. Michael Wetter, a Microsoft corporate development executive, further testified via video deposition that Microsoft has recognized approximately $9.5 billion in revenue from its OpenAI partnership as of March 2025.
Musk departed the OpenAI board in 2018 following disagreements over its strategic direction, including a failed attempt to merge it with his automaker Tesla. Subsequently, OpenAI established a for-profit subsidiary, facilitating external funding. This for-profit arm has since attracted billions from investors like Microsoft, propelling its valuation to over $850 billion.
Recalling the dramatic events of November 2023 when Altman was briefly fired by the OpenAI board for "not consistently candid" communications, Nadella described himself as "pretty surprised." His immediate priority, he said, was ensuring continuity for Microsoft customers. Nadella sought clarification from the board but found their explanation insufficient, labeling the situation "amateur city." He suspected "jealousy and poor communication" might have been at play.
In October, OpenAI underwent a recapitalization, solidifying its structure with a non-profit holding an equity stake in its for-profit entity. Microsoft subsequently disclosed a roughly 27% stake in OpenAI's for-profit unit, valued at approximately $135 billion.
Microsoft CEO Satya Nadella is questioned by Microsoft attorney Jay Jurata during Elon Musk's lawsuit trial over OpenAI's for-profit conversion at a federal courthouse in Oakland, California, U.S., May 11, 2026 in a courtroom sketch. Vicki Behringer | Reuters
Despite recent signs of strain, both companies continue to emphasize their partnership's strategic importance. A revamped agreement announced last month allows OpenAI to cap revenue share payments and utilize any cloud provider, aiming to "simplify our partnership." Musk, while not entirely against a for-profit OpenAI, views it as "the tail wagging the dog," accusing Altman and Brockman of self-enrichment while benefiting from a non-profit's positive image. He questioned the implications of Microsoft controlling "digital superintelligence."
Nadella refuted a claim by former OpenAI director Tasha McCauley, who recalled him wanting to restore Altman to his position. Nadella testified he never demanded Altman's reinstatement. He also addressed text messages with Microsoft tech chief Kevin Scott regarding potential OpenAI board candidates, explaining his opposition to Diane Greene joining due to her recent affiliation with Google, a major Microsoft competitor in AI.
Molo, Musk's lawyer, highlighted an email Nadella sent in 2022 to Microsoft executives stating, "I don't want to be IBM and OpenAI to be Microsoft." Nadella confirmed this referenced IBM's non-exclusive deal with Microsoft for DOS, which eventually allowed Microsoft to become a much larger company. As of market close Monday, Microsoft's market cap stood at $3 trillion, significantly dwarfing IBM's $210 billion.
OpenAI co-founder Sutskever takes the stand
Following Nadella, Ilya Sutskever, an OpenAI co-founder and esteemed AI researcher, testified about his decision to join the company, communications with Musk, and his role in Altman's ouster. Sutskever, who previously worked at Google, declined a $6 million annual offer to stay, driven by his "great deal of ownership" over OpenAI and a desire to prevent its "destruction."
OpenAI co-founder Ilya Sutskever is questioned by Elon Musk's lawyer Steven Molo during Musk's lawsuit trial over OpenAI's for-profit conversion at a federal courthouse in Oakland, California, U.S., May 11, 2026 in a courtroom sketch. Vicki Behringer | Reuters
Bret Taylor, OpenAI's board chairman, followed Sutskever, detailing OpenAI's structure and the "dire" period surrounding Altman's removal. Taylor's testimony will resume on Tuesday.
Video: The Musk vs. OpenAI trial is underway — here’s where things stand (3:11)
