Both the major cryptocurrencies fell heavily over the weekend, continuing a recent trend of increased volatility.
Bitcoin fell below $US2,000 for the first time since May 17, and hit a weekend low of $US1,758.20 before rallying back towards $US1,900.
Bitcoin continues to be plagued by uncertainty stemming from disagreements among the currency's developers over how best to run the blockchain platform Bitcoin is traded on.
In one camp, developers want the transaction capability of the Bitcoin network to be significantly increased. The other side argue that maintaining a cap helps protect the security of the platform.
Market analysts will be watching when a test run of a revised platform with quicker transaction speeds is implemented on July 21. If the higher-speed network is taken up by more than 80% of market participants, then it will likely be introduced permanently from August 1.
Meanwhile, Ethereum lost around 25% of its value of the weekend and a short time ago was trading at $US155 after dipping below $US140 overnight.
That's well off the peak of around $US370 in mid-June, with the price of an Ether token having lost more than half its value since then.
While volatility in crytocurrencies is nothing new, as the markets mature and gain more interest it looks like the significant market fluctuations are here to stay for now.