In the span of eight minutes, <a href="https://www.thenationalnews.com/business/2022/08/26/us-households-to-feel-some-pain-as-fed-fights-inflation-jerome-powell-says/" target="_blank">Federal Reserve chairman Jerome Powell sparked a market rout</a> that cut the fortunes of America’s richest people by $78 billion. <a href="https://www.thenationalnews.com/business/technology/2022/08/19/elon-musk-accuses-twitter-of-hounding-him-for-chats-about-stalled-buyout/" target="_blank">Tesla founder and chief executive Elon Musk</a> saw $5.5bn erased from his wealth. <a href="https://www.thenationalnews.com/business/money/2022/07/04/jeff-bezos-criticises-joe-biden-for-calling-on-fuel-companies-to-lower-prices-at-the-pump/" target="_blank">Amazon founder Jeff Bezos </a>lost $6.8bn, the most of anyone on the Bloomberg Billionaires Index. The fortunes of <a href="https://www.thenationalnews.com/business/money/2022/07/22/indias-gautam-adani-becomes-worlds-4th-richest-person-after-overtaking-bill-gates/" target="_blank">Microsoft co-founder Bill Gates</a> and legendary investor <a href="https://www.thenationalnews.com/business/energy/2022/08/20/why-buffetts-berkshire-hathaway-is-seeking-to-buy-up-to-50-of-occidental/" target="_blank">Warren Buffett </a>declined by $2.2bn and $2.7bn, respectively, while <a href="https://www.thenationalnews.com/business/money/2022/06/20/google-co-founder-and-worlds-sixth-richest-person-sergey-brin-files-for-divorce/" target="_blank">Google co-founder Sergey Brin</a>’s was knocked below $100bn. Mr Powell used his speech at the Kansas City Fed’s annual policy forum in Jackson Hole, Wyoming, to reiterate that the US central bank will keep raising interest rates and probably leave them there for a while to reduce inflation. He was seen as pushing back on a recent rally in US stocks that was fuelled by speculation that policy makers would soon reverse course from their tightening. The S&P 500 tumbled 3.4 per cent, its worst day since mid-June. The tech-heavy Nasdaq 100, which counts Microsoft, Amazon, Tesla and Alphabet among its biggest components, fell more than 4 per cent. Few billionaire fortunes have been spared this year. The world’s 500 richest people lost $1.4 trillion in the first half of 2022, the steepest six-month drop yet for the wealthiest people on the planet. But US stocks in July posted their strongest monthly advance since November 2020, leading investors to wager that the worst of the market rout was over. Instead, Mr Powell’s speech served as a reminder that valuations of technology companies remain high by historical standards after an unprecedented run-up during the coronavirus pandemic, when interest rates were pinned near zero.