Bitcoin dropped below US$7000 (HZ$10,000) to trade more than 5 percent down on the day, having fallen by well over US$1000 since hitting an all-time high on Wednesday.
On Friday Bitcoin dropped to US$6,800 on the Luxembourg-based Bitstamp exchange at lunchtime, before recovering a little to US$6870 just over 20 minutes later.
On Wednesday, it had touched US$7888 after a software upgrade planned for next week that could have split the cryptocurrency in two was suspended.
As bitcoin fell, Bitcoin Cash - a clone of the original that was generated from another split on August1 - surged, trading up as much as 35 percent on the day at around US$850, according to industry website Coinmarketcap.
Despite losing almost 7 percent this week, bitcoin is still up more than 600 percent so far this year.