The value of Bitcoin has fallen below $5,000 (£3,889) for the first time since October 2017.
The fall brought the total value of all Bitcoin in existence to below $87bn.
On Thursday, 15 November, Bitcoin Cash - an offshoot of Bitcoin - split into two different crypto-currencies, which are now in competition with each other.
And some observers have blamed this for creating turmoil in the crypto-currency markets, with many of the digital assets experiencing falls.
Bitcoin exchange Kraken said in a blog post that it regarded one of the two new Bitcoin Cash crypto-currencies - Bitcoin SV - as "an extremely risky investment".
Bitcoin is a notoriously volatile crypto-currency.
At its peak, in November 2017, it briefly hit $19,783 - which means the price has fallen by about 75%.
Source: bbc