By Tom Wilson
LONDON (Reuters) - Digital currencies Ethereum and XRP soared on Monday, gaining momentum as bitcoin powered on towards its all-time high.
Ethereum, the second largest cryptocurrency by market capitalisation after bitcoin, jumped 7% to its highest since June 2018, taking its gains to more than 25% over the last three days alone.
Traders said ethereum, which often moves in tandem with bitcoin, has been boosted by growing demand ahead of an upgrade to its blockchain network - due in early December - that is widely expected to make it quicker and more secure.
The upgrade could mean "more people and businesses can use ethereum for economic activity, rather than just financial trading," said Ross Middleton, co-founder of cryptocurrency exchange DeversiFi.
Ethereum, like bitcoin, is mostly popular among speculative traders. It has gained little mainstream use.
Third-biggest coin XRP soared 22% to its highest in over two years. It has gained around 75% in the last three days, though two traders said there was no immediate news catalyst for its jump.
The price of these so-called altcoins is closely tied to bitcoin. Less liquid than their bigger cousin, they tend to suffer from even greater volatility than the original cryptocurrency.
Smaller coins have rallied as crypto investors took gains from bitcoin's stunning recent rally, which has seen it rise around 10% in the last week.
Bitcoin was last up 1% at $18,603, its all-time high of $19,666 hit in Dec. 2017 in sight. It has soared around 160% this year.
"Bitcoin skyrocketed, profits were taken, profits went back into altcoins," said Joseph Edwards, head of research at crypto brokerage Enigma Securities.
Bitcoin's gains have been fuelled by a demand for risk-on assets amid unprecedented stimulus measures to combat the damage from the COVID-19 pandemic.
With governments and central banks in full stimulus mode, investors have also sought out bitcoin for its perceived resistance to inflation.