Bitcoin (BTC) tumbled overnight, with the leading cryptocurrency dropping to levels as low as $19,621, according to data from CoinMarketCap. Last week was a bullish one for cryptocurrencies, as most ended up in the green territory. BTC had also managed to stay above its $20,000 support after weeks of waffling above and below this price. Bitcoin has this morning, however, shed 3.72pc over the past 24 hours and is trading closely near its seven-day low of $19,341.23, indicates CoinMarketCap.The market capitalization of the largest cryptocurrency, Bitcoin, has crashed from a whopping $1.27 trillion in November 2021 to under $377b today.