xAI logo is seen in this illustration taken, February 16, 2025. REUTERS/Dado Ruvic/Illustration

(Reuters) -Billionaire Elon Musk's xAI has raised $15 billion in a series E funding round, CNBC reported on Thursday, citing sources familiar with the matter.

The capital adds another $5 billion to the $10 billion round it raised in September that valued it at $200 billion, the report said.

Following CNBC's September report, Musk said the company was not raising any capital.

XAI, in what seemed like an automated reply, said "Legacy Media Lies" in response to a Reuters request for comment on Thursday's raise.

The AI startup has been ramping up its data center capacity to train more advanced models, as it looks to compete more effectively with OpenAI's ChatGPT and Anthropic's Claude.

A lot of the money raised will fund graphic processing units that underpin large language models, the report said.

Investor enthusiasm in artificial intelligence firms has remained strong even as fears of an AI bubble emerge due to sky high valuations and massive spending plans.

XAI is also investing heavily to expand its own infrastructure by buying property in the Memphis to build out its planned Colossus supercomputer.

Elon Musk did not immediately respond to a Reuters request for comment.

(Reporting by Zaheer Kachwala in Bengaluru; Editing by Anil D'Silva)