Elon Musk's X is now valued at less than a quarter of its $44 billion purchase price, according to a new estimate from Fidelity. Fidelity, which helped Musk acquire X, values its stake in the company at approximately $4.19 million, based on newly released disclosures. The fund has reduced the value of its holding in X by a total of 78.7% as of the end of August.