Elon Musk's artificial intelligence business, X.AI, has filed with the SEC to raise up to $1 billion in a stock offering.

According to the filing, the business has already raised approximately $135 million from four investors.

 The first sale took place on Nov. 29 and has a "binding and enforceable agreement" for the acquisition of the remaining shares.

According to its website, Musk's AI business attempts to "understand the true nature of the universe," which he launched in July.

X.AI debuted a chatbot dubbed Grok last month, which the business claims is based on "The Hitchhiker's Guide to the Galaxy."

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