Billionaire <a href="https://www.thenationalnews.com/opinion/comment/2022/06/03/at-davos-bill-gates-proved-he-is-a-true-problem-solver/" target="_blank">Microsoft co-founder Bill Gates</a> dismissed cryptocurrency projects such as <a href="https://www.thenationalnews.com/business/2022/06/02/ex-employee-of-nft-marketplace-opensea-arrested-for-insider-trading/" target="_blank">non-fungible tokens</a> (NFTs) as shams “based on the greater-fool theory” at a climate conference on Tuesday, reviving past criticism of digital assets. “Obviously, expensive <a href="https://www.thenationalnews.com/business/cryptocurrencies/2022/05/01/ethereum-crashes-as-bored-ape-metaverse-land-frenzy-raises-320m/" target="_blank">digital images of monkeys</a> are going to improve the world immensely,” Mr Gates said sarcastically while speaking at the event in Berkeley, California. He is neither long nor short on the asset class, he said. It is not the first time Mr Gates, who is also the co-chairman of the Bill & Melinda Gates Foundation, has criticised cryptocurrencies. He sparred with billionaire Tesla chief executive Elon Musk last year over whether Bitcoin was too risky for retail investors and the environmental harm of mining coins. Mr Gates, the world's fourth-richest person with a net worth of $113 billion, according to the Bloomberg Billionaires Index, was speaking at the climate event as the founder of Breakthrough Energy Ventures, the climate-focused fund he began in 2015. He also noted the difficulty of recruiting Silicon Valley engineers to work in industries such as chemicals and steel production that are in need of lower greenhouse gas emissions. Bitcoin fell by more than 15 per cent on Monday and by another 5.4 per cent on Tuesday, part of a <a href="https://www.thenationalnews.com/business/cryptocurrencies/2022/06/14/why-are-bitcoin-and-other-cryptocurrencies-crashing/" target="_blank">broader cryptocurrency sell-off </a>fuelled by higher-than-forecast US inflation and the halt of withdrawals by the lending platform Celsius. The digital token is currently trading 8.52 per cent lower at $20,909.11 as of 9.27am UAE time on Wednesday. Popular NFT collections, including the celebrity-favoured Bored Ape Yacht Club (BAYC), are also being hit hard. Mr Gates also defended digital banking efforts he has supported through his philanthropic foundations, which he described as “hundreds of times more efficient” than cryptocurrencies.