John Jumper, Google DeepMind's Vice President, and Noam Shazeer, the Gemini model's co-lead, left Alphabet for new employers in June, with Jumper departing for Anthropic. Alphabet's stock lost over 6% of its value -- about $250 billion -- in just the past few days, apparently due to Jumper's departure announcement. The article notes that Alphabet's stock was trading at a fairly unusual premium prior to its recent sell-off and, even after the sell-off, is trading at a high valuation from a historical perspective, near the most expensive level it has seen in the past decade based on its cash from operations metric. The sell-off also coincided with a broader sell-off in the AI space.