Bitcoin's price has plummeted after Elon Musk refused to deny that Tesla has sold its entire $1.2 billion cryptocurrency holding.

As the market tried to make sense of a brief exchange between Mr. Musk and a crypto enthusiast on Twitter, Bitcoin fell below US$45,000 ($57,800) for the first time in three months today.

Tesla had sold all of its Bitcoin, according to a Twitter account with the handle CryptoWhale, which said it would be verified at the end of the current quarter.

"When Bitcoiners find out Tesla dumped the majority of their bitcoin holdings next quarter, they're going to slap themselves," CryptoWhale wrote.

"I wouldn't blame Elon Musk, given the amount of hate he receives," the tweet added.

Mr. Musk responded, "Indeed," in a one-word response that sent the Bitcoin price plummeting.

Last week, the price of Bitcoin plummeted after Elon Musk announced that Tesla will no longer accept Bitcoin as payment for electric vehicles.

After months of being bullish on Bitcoin, Mr. Musk cited its high environmental cost as the reason for the switch.

Tesla revealed in February that it invested $1.9 billion of its available cash in Bitcoin.

Tesla said last month during its quarterly earnings call that it had sold 10% of its Bitcoin holdings, netting a $130 million profit.