Experts say the rally in bitcoin still has a long way to go, after the cryptocurrency reached a new all-time high of $US3525 this week.

The latest price surge has been driven by the rise and fall of bitcoin cash – a secondary cryptocurrency – and an update in the underlying bitcoin software, which paves the way for an evolution of the bitcoin blockchain.

The value of cryptocurrencies is soaring after a mammoth change in bitcoin software. Credit:Bloomberg

The update – called SegWit – is the product of months of internal debate within the cryptocurrency community around how to handle the rapid increase in transaction demands.

A byproduct of this debate was the creation of bitcoin cash, another coin, duplicated from the original, that ran on a different software.