A California judge has dealt a blow to Elon Musk's $134 billion lawsuit against OpenAI and Microsoft by suggesting the billionaire's damage claims rest on 'numbers out of the air'. Judge Yvonne Gonzalez Rogers expressed skepticism during a recent hearing about the methodology used by Musk's expert witness, economist C Paul Wazzan, who calculated Musk's contributions accounted for 50-75% of OpenAI's value. While Rogers did not exclude Wazzan's testimony, she indicated a jury would likely view the calculations as unpersuasive.

The lawsuit centers on Musk's claim that OpenAI breached its original non-profit mission after he provided early funding and support, now valued at $730bn. If successful, damages could total $109bn for OpenAI and $25bn for Microsoft.