Most Read from BloombergThe Bloomberg Magnificent 7 Index was down 4.8% midway through Thursday's session, wiping out roughly $767 billion in market valuation. The declines were led by Tesla and Alphabet, who spooked Wall Street with their earnings on Wednesday. "The real problem is the amount of spend that's going on," said Ken Mahoney, chief executive officer of Mahoney Asset Management. The macro backdrop, including oil prices rising as the war with Iran escalates, is increasingly the pressure on these stocks, he added. Other major AI spenders also fell, with Microsoft Corp. down 3.1%, Amazon.com Inc. sinking 5% and Meta Platforms Inc. declining 4.7%.