The first upgrade to bitcoin’s protocol in four years has led some cryptocurrency experts to declare it significantly enhances the functionality of the digital asset, overshadowing even Elon Musk’s grip on its valuation.

Bitcoin passed through the $US40,000 ($52,000) threshold taking its weekly gain to 23 per cent following a heavy few days of headlines that keep knocking its price around. On Sunday, Musk conceded that Tesla would resume support for bitcoin, conditional upon it being mined with a sufficient proportion of renewable energy.