Alphabet Shares Drop 6% as Top AI Developers Shift to Anthropic and OpenAI

Alphabet shares plummeted 6% on Monday after two of Google’s top AI researchers announced exits to Anthropic and OpenAI. The back-to-back departures wiped out roughly $250 billion in market cap.

Wall Street is now openly debating whether Google is falling behind in the war for frontier AI talent.

Who Left Google and Where They Are Heading

A frontier AI researcher is a scientist whose work shapes the next generation of large language models and foundational systems. Two of the most senior figures at Google just walked out the door, taking their playbook and reputation with them across the table.

John Jumper announced over the weekend that he is leaving Google DeepMind after nearly nine years to join Anthropic. He served as Vice President and Engineering Fellow, leading the team behind AlphaFold2 across his career inside the lab.

A bit of news: After nearly 9 years, I have decided to leave Google DeepMind and join Anthropic (after taking some time to recharge). I am incredibly grateful for my time at GDM. @demishassabis took a real chance letting me lead the AlphaFold team just six months after finishing…

— John Jumper (@JohnJumperSci) June 19, 2026

Jumper is not a typical hire. He shared the 2024 Nobel Prize in Chemistry with Demis Hassabis for the protein-folding model that already mapped more than 200 million structures. As a result, his move to Anthropic instantly reshapes the credibility map for AI for science.

Days earlier, Noam Shazeer made an equally dramatic exit. The Gemini co-lead and Vice President of Engineering jumped to OpenAI on June 18, less than two years after Google paid $2.7 billion to bring him back through the Character AI acquisition.

Shazeer carries even deeper historical weight in the industry. He co-authored the 2017 “Attention Is All You Need” paper at Google Brain, the foundational work that introduced the Transformer architecture now underlying every major language model in production.

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I’m excited to share that I’ll be joining OpenAI and look forward to working with the exceptional team there.It was a difficult decision to move on. I’m incredibly proud of the amazing team at Google and everything we’ve built together. It has been an honor and a pleasure to…

— Noam Shazeer (@NoamShazeer) June 18, 2026

Anthropic’s pull was strong on both sides. The startup is reportedly in talks at a valuation near $1 trillion. Furthermore, Polymarket traders are pricing a roughly 74% probability of an Anthropic IPO before the end of the year.

Why Wall Street Punished Alphabet So Hard

The stock fell as much as 7.2% intraday, the steepest drop since February. Alphabet ended the day around 6% lower, posting its worst trading session in roughly a year. Moreover, the slide erased nearly $250 billion in market cap.

Analyst commentary turned sharply fast. D.A. Davidson head of technology research Gil Luria warned that “Google is losing the war for talent at the frontier of AI.” He added that the departures suggest Google may now be falling visibly behind.

Vital Knowledge founder Adam Crisafulli echoed the call. He said that “OpenAI and Anthropic are increasingly the dominant frontier firms” in the United States and appear to be pulling away from Google, Meta, and xAI in terms of model and coding tool capabilities.

The selloff also spread across Big Tech. The Bloomberg Magnificent Seven index dropped as much as 2.2% on Monday. Furthermore, Amazon fell as much as 5%, while Meta and Microsoft both lost more than 3% during the session.

Spending pressures compounded the pain. Alphabet announced earlier this month an $80 billion equity raise to fund capital expenditures for artificial intelligence. Total AI spending now projects between $180 billion and $190 billion for the entire year.

The bigger question is structural. Investors are increasingly rotating out of firms paying for AI compute and into companies receiving the checks.

Whether Google can retain its remaining stars or reverse the narrative will define how the stock trades across the rest of 2026.