Key Takeaways Shares of C3.ai lost a quarter of their value after the AI software provider posted preliminary sales figures that were significantly weaker than expected.CEO Tom Siebel called the sales results “completely unacceptable” and blamed a reorganization of leadership and his health as contributing factors.

C3.ai stock was plunging as it said quarterly revenue would fall way below expectations. There are further problems ahead.

C3.ai reported expected revenue of $70.2 million to $70.4 million, down 19% year-over-year from $87.2 million in the year-ago quarter. This was well below the company's own guidance midpoint of $104.5 million.