Cryptocurrency prices gave ground on Sunday, extending the losses of a "brutal" week.

A "distressing week" for cryptocurrencies. That's how CNN refers to the trading of digital currencies in recent sessions, culminating with a 13% drop in bitcoin.

Bitcoin, which accounts for more than 45% of the global cryptocurrency market, traded this Sunday morning around $33,000, already quite far from its all-time high above $64,000 reached a month ago.

Electric vehicle maker Tesla's CEO Elon Musk, whose tweets regularly influence the digital currency market, stressed his support for cryptocurrencies yesterday, which breathed some life into bitcoin - which rose to $38,000 - after a tumultuous week, but wasn't enough to keep the currency in the green.

Musk has said he supports cryptocurrencies in the "battle" against fiat currency. But that hasn't reassured the market for long, not least because the Tesla CEO has revealed disparate positions.

On the 12th, Musk announced on Twitter that Tesla would no longer accept bitcoins in the sale of its cars. This is due to fears surrounding the "rapidly growing use of fossil fuels for the mining and transaction of bitcoins."

Other cryptocurrencies also lost ground over this weekend. Ethereum retreated 20% this morning, trading around $1,900. Dogecoin, meanwhile, dipped 16% and binance coin sank 26%.

Cryptocurrency markets, remember, are open 24 hours a day, seven days a week. 

On Wednesday, May 19, a vast downward movement of cryptocurrencies eclipsed a billion dollars of market value. The selloff movement began after Chinese authorities announced additional restrictions on cryptocurrency transactions on their territory.

US regulators are also pointing to new restrictions, with the Treasury Department saying that any new digital currency transfers worth $10,000 or more must be reported to the IRS.

This kind of volatility in the crypto sector is nothing new and interest in this market remains high. Despite the declines in recent sessions, bitcoin has accumulated a gain of over 250% in the last 12 months.