Bitcoin fell below $6,000 late Monday — for the first time since June — against a backdrop of cryptocurrencies declining in value.
The world's largest digital currency by market value tumbled as low as $5,900 at around 10 p.m. ET, and was down around 4 percent, according to CoinDesk index data, which tracks prices from several exchanges.
The cryptocurrency's price is close to its lowest point of the year. The lowest level of 2018 was reached in June 18, when it retreated to $5,785.
Rival coins ether , the digital token of the ethereum blockchain, and XRP , Ripple's digital asset, fell alongside bitcoin. Ether toppled almost 6 percent to around $270 at 1:53 a.m. ET, while XRP fell 5.7 percent to a price of 26 cents.
The latest rout among digital coins followed a rally last month that saw bitcoin climb to a price above $8,000. News of institutional interest in the space by the likes of asset management giant BlackRock , as well as a collaboration between New York Stock Exchange owner Intercontinental Exchange , Starbucks and Microsoft on a digital asset platform, had lifted sentiment in the market.
It resulted in the total market capitalization of all cryptocurrencies — worked out by multiplying the prices of the digital assets by the total volume of coins in circulation — falling by $21 billion in the last 24 hours.
According to Charles Hayter, chief executive of digital comparison site CryptoCompare, the downward move in cryptocurrencies was on the back of the postponement of a bitcoin exchange-traded fund (ETF) proposed by VanEck and Solid X.
If it were to be greenlit by the U.S. Securities and Exchange Commission (SEC), the VanEck Solid X ETF would be the first to track cryptocurrency assets.
Hayter described Monday's sell-off as "momentum-based selling following the ETF kickback," and "the usual gyrations of a market in a depressed mode."
The SEC's move to delay a decision on the VanEck Solid X bitcoin trust ETF to September 30 followed the regulator's rejection of a separate ETF proposal from the Winklevoss twins. Cameron and Tyler Winklevoss had made a second attempt to list shares of a bitcoin ETF, which would have been commodity-based.
Bitcoin has recently recovered its dominance in the market as several so-called "altcoins," or alternative cryptocurrencies, have plummeted in value. It is still, however, roughly 70 percent off the $19,783 all-time high it notched late last year.