Joachim Klement, market strategist at Panmure Liberum in London, warned the AI-driven investment boom could unwind as early as 2027–28 and spark the worst S&P 500 sell-off since the 2008 financial crisis. "My core view is that the AI bubble will burst in 2027 or 2028 — sometime within the next two years," he said, citing hyperscalers' free cash flow being effectively depleted and rapidly rising borrowing costs as key vulnerabilities. Klement sets an end-2027 S&P 500 target of 5,000, implying rou

Joachim Klement, market strategist at Panmure Liberum in London, warned the AI-driven investment boom could unwind as early as 2027–28 and spark the worst S&P 500 sell-off since the 2008 financial crisis. "My core view is that the AI bubble will burst in 2027 or 2028 — sometime within the next two years," he said, citing hyperscalers' free cash flow being effectively depleted and rapidly rising borrowing costs as key vulnerabilities. Klement sets an end-2027 S&P 500 target of 5,000, implying roughly a 36% drop from current levels.