Alphabet shares tumble 7% as second AI leader departs

Alphabet just lost one of the most important names in artificial intelligence. Noam Shazeer, co-lead of Google’s Gemini AI models and co-author of the 2017 Transformer paper that essentially birthed modern AI, announced he’s leaving for OpenAI.

Alphabet brought Shazeer back less than two years ago through a $2.7 billion deal that involved acquiring parts of his startup Character.AI.

The $2.7 billion boomerang

Shazeer took to social media on June 18 to announce his move, expressing enthusiasm about joining OpenAI’s team. The Transformer paper he co-authored in 2017 is arguably the single most consequential piece of AI research in the last decade, serving as the architectural backbone for virtually every large language model in existence today, from GPT to Gemini itself.

His departure is the second major AI leadership exit from Alphabet in recent months, part of a broader talent migration that has seen multiple high-profile researchers and engineers leave for competitors.

Alphabet’s stock dropped approximately 7% earlier in the cycle, a decline tied to earnings misses and concerns about the company’s massive AI spending commitments. The company had already outlined plans for $75 billion in AI infrastructure expenditures. More recently, Alphabet announced an $80 billion equity raise in June 2026, which prompted a further 4% decline in the stock price.

What this means for investors

The company is spending tens of billions on AI infrastructure while simultaneously watching some of its best minds walk out the door. The $75 billion in planned AI infrastructure spending only makes sense if the people deploying that infrastructure are world-class.

OpenAI, already considered a leader in generative AI, now adds a researcher whose fingerprints are on the very architecture their models are built upon. Shazeer’s deep understanding of transformer models and his experience scaling Gemini could accelerate OpenAI’s development roadmap in tangible ways.

One area where this story doesn’t appear to have much impact: crypto. Searches across major crypto-focused outlets turned up no meaningful connections between Shazeer’s departure and digital asset markets.

The stock’s 7% decline reflects more than just one person leaving. It reflects a growing anxiety that Alphabet’s AI ambitions, backed by some of the largest capital commitments in corporate history, may be undermined by an inability to keep the people who matter most.

Disclosure: This article was edited by Editorial Team. For more information on how we create and review content, see our Editorial Policy.