Bitcoin extends slide to below $4,500; loses 30% in a week

Other cryptocurrencies also fell sharply, with Ethereum's ether losing 10 percent and Ripple's XRP down 13 percent in a largely sentiment-driven slide.

Bitcoin tumbled more than 7.5 percent on Tuesday to below $4,500, knocking off nearly a third in value of the world's best-known cryptocurrency's losses within a week as a selloff in digital currencies intensified across the board.

Other cryptocurrencies also fell sharply, with Ethereum's ether losing 10 percent and Ripple's XRP down 13 percent in a largely sentiment-driven slide.

Bitcoin is now trading at $4,354.20, its lowest level on the Bitstamp exchange since October 2017.