Hassabis steps down as DeepMind CEO — Alphabet stock drops on the shakeup

On Wednesday, Alphabet announced its largest AI leadership overhaul yet. Demis Hassabis, the Nobel laureate who has run Google DeepMind since its founding, is stepping down from day-to-day leadership to take on a newly created role: chief scientist of Alphabet, while staying on as DeepMind's chairman. Daily operations move to Koray Kavukcuoglu, DeepMind's CTO and, as colleagues have called him, Google's "chief AI architect" for 13 years — he now reports directly to Sundar Pichai and owns Gemini model development, Frontier AI research, and the Gemini app and developer teams.

The same day, Jeff Dean — one of Google's best-known engineers, with 27 years at the company — left to launch a new startup, Discovery Loop, alongside fellow researcher Sanjay Ghemawat and two other former Googlers. The venture is a public benefit corporation focused on automating machine learning and scientific research. Pichai framed Dean's exit as voluntary: "After an incredible 27-year run, Jeff Dean is at a moment where he wants to try something new." A Google spokesperson said the two announcements, despite landing on the same day, weren't directly connected — but the timing is notable regardless: the flagship Gemini model remains months behind its original June target, fueling investor concern that Google is falling behind Anthropic and OpenAI.

• Hassabis stays on as DeepMind chairman but hands day-to-day control to Kavukcuoglu
• Jeff Dean and Sanjay Ghemawat depart to launch startup Discovery Loop
• Alphabet shares fell roughly 5% on the day of the announcement

“I've been working towards AGI my whole life and now, like many of you, I feel it is close at hand. It's critical that we collectively get the next steps right to ensure this all goes well for humanity.”

— Demis Hassabis, Alphabet's Chief Scientist

Back in July, Hassabis himself publicly urged the creation of an international oversight body for AGI — and now his own role at the company is shifting against the backdrop of the very arrival he warned about. We've covered Gemini and Google DeepMind's full story before, from the merger of its research teams to its status as Google's biggest AI bet — this leadership reshuffle is the latest chapter.

None of this should be read as personalized investment advice.