GoKawiilGoogle ended its worst day on the stock market in over a year, as artificial intelligence concerns mounted and two high-profile researchers departed for rivals in recent days.
Shares of parent company Alphabet closed down about 5% on Monday, underperforming both the Nasdaq and the other tech megacaps. It was the steepest slide since about a 7% decline in May 2025.
The brain drain concerns began last week when Google's vice president of engineering and a co-lead of its Gemini AI models, Noam Shazeer, announced Wednesday that he was leaving the company to join rival OpenAI. Shazeer's departure came less than two years after he returned to Google.
In August 2024, Google brought back Shazeer and fellow researcher Daniel De Freitas to its DeepMind AI unit as part of a partnership with startup Character.AI, which the pair founded after leaving Google in 2021.
The departure came weeks after Google unveiled new AI products, including its Gemini 3.5 Flash model and Gemini Spark AI agent, at its annual I/O developer conference.