The money manager is on the stand. The president is next.

Day four of the OpenAI trial began Thursday in Oakland with Jared Birchall, the head of Elon Musk's family office, taking the witness stand. CNBC's live blog confirmed Birchall was sworn in after Musk wrapped his three days of testimony with a final cross-examination by Sam Altman's attorney. Greg Brockman, OpenAI's co-founder and president, sits behind defense counsel with a yellow legal pad. Anthropic was not in the courtroom. They never are.

Birchall manages Musk's reported $400 billion-plus net worth and oversaw the $38 million in donations Musk says he made to seed OpenAI as a nonprofit. His testimony is being run by Musk's legal team to establish the chain of intent: that the money was given on the express understanding that OpenAI would remain a charity dedicated to open-sourcing AI research, not a for-profit company building Mythos for the federal government.

Why Birchall matters more than the press is treating it.

Most of the trial coverage has framed Birchall as a procedural witness. He is not. He is the bookkeeper. If Musk's case turns on whether OpenAI breached an implied charitable trust, the documentation Birchall maintained on the donations is the cleanest evidence in the entire proceeding. Email exchanges, wire instructions, and tax filings all sit on his desk. Altman's defense, led by Latham and Watkins, will try to extract concessions that the donations were structured as ordinary charitable gifts with no restrictive covenant. Musk's team will try to do the opposite.

The judge, Yvonne Gonzalez Rogers, has already telegraphed how she reads the case. Earlier this week she pushed OpenAI's counsel to give 48 hours notice on Brockman, signaling she wants the co-founder under oath before the week closes. Wired reported Brockman has been writing on his legal pad throughout Musk's cross, occasionally looking up to examine the 2017 emails being displayed as evidence. The diary entry calling the nonprofit promise a lie is the document the case actually turns on. Brockman wrote it.

What we learn today.

If Birchall finishes by Thursday close, Brockman is the first witness Friday. That puts the highest-stakes testimony of the trial inside a 24-hour window. Altman is not on the witness list this week, which is itself a tell: the defense is keeping its CEO away from the stand until they see how Brockman's cross goes. Stuart Russell, the Berkeley AI safety expert, is queued behind Brockman per Reuters' filings.

The trial is expected to run several more weeks. The verdict, when it lands, will set the precedent for how American courts treat the for-profit conversion of any nonprofit research lab. Anthropic, xAI, and DeepMind all have varying degrees of structural exposure to the doctrine being tested in real time on the seventh floor of the Oakland federal courthouse. Nobody outside the litigation teams is being honest about that.

First reported by CNBC, Reuters, NYT, and Wired live blogs. Birchall sworn in Thursday, April 30. Brockman 48-hour notice issued Wednesday, April 29.