Twitter is now worth only about $15 billion, a massive 33 per cent lower than $44 billion Elon Musk and his co-investors paid to acquire the platform, the media reported on Wednesday.
Twitter has struggled financially since Musk took over.
The financial services giant Fidelity estimated in its monthly report of portfolio valuations that Twitter is now worth just one-third worth of what Musk paid for the micro-blogging platform, reports Bloomberg.
Musk's investment in Twitter is now worth $8.8 billion. The outgoing Twitter CEO spent over $25 billion to acquire an estimated 79 per cent stake in the company in October last year.
He earlier acknowledged that he overpaid to acquire Twitter, including $33.5 billion in equity.
"Although obviously myself and the other investors are obviously overpaying for Twitter right now, the long-term potential for Twitter in my view is an order of magnitude greater than its current value," Musk had said during Tesla's earnings call in October last year.
"I'm excited about the Twitter situation, because obviously I know their product incredibly well," he said. "And I think it's an asset that has sort of languished for a long time but has incredible potential."
Fidelity first reduced the value of its Twitter stake in November, to 44 per cent of the purchase price. That was followed by further markdowns, the report mentioned.
Fidelity's Twitter stake, which now comes under Musk's X Holdings, was valued at almost $6.55 million (as of late April).
Going through a churning with just about 1,500 employees left from an earlier 7,500-strong workforce, Twitter is finding it difficult to make strong profits.