Tesla, Inc. chief executive Elon Musk says the electric-motor-vehicle manufacturer has, or is likely to, sell about $1.5 billion in Bitcoin.

His Twitter exchange Sunday sent the cryptocurrency's price into decline. As of 07:10 GMT Bitcoin was trading at $44,557.92 each - down 8.94% over the previous 24 hours. $79.08 billion was traded in the period, according to data from Coindesk. Bitcoin was projected to open even lower in US trading hours.

 "Indeed," Musk responded over the weekend to a Twitter post which warned that "Bitcoiners are going to slap themselves next quarter when they find out Tesla dumped the rest of (its) Bitcoin holdings."

Last week, the business owner said the company wouldn't buy more bitcoin until the cryptocurrency, which is mined using computers with heavy electricity requirements, became more ecologically friendly.

Tesla made a $1.5 billion investment in Bitcoin early February - around the same time the company said it would start accepting the cryptocurrency for car purchases. Tesla's Bitcoin holdings have netted an additional $101 million in the past quarter, filings show.

But May 12 the electric vehicle manufacturer announced it had "suspended vehicle purchases with Bitcoin" owing to the "rapidly increasing use of fossil fuels for bitcoin mining."

Investors reacted quickly and Bitcoin prices fell 5% in the minutes after Musk's announcement - wiping about $6.1 billion from the currency's market capitalization.

Cryptocurrency market stocks as a whole dropped 17% in response.

Musk "is playing games. It is hard to take anyone who does that seriously," venture capital investor Fred Wilson tweeted late Friday. "I've lost enormous respect for him over the last year because of it."

Musk had been an outspoken supporter of several cryptocurrencies. His social media posts in favor of Bitcoin, Ethereum and Dogecoin have led to several substantial price rises over the last year.

In a recent "Saturday Night Live" cold open he signaled his endorsement for Dogecoin. The move backfired - prompting a small dip in value ahead of the show.