Alphabet shares surged more than 5% on Monday, closing above $300 for the first time in the company’s history. The rally followed strong investor enthusiasm surrounding the launch of Google’s Gemini 3 AI model, which the company positioned as a major step forward in its generative AI roadmap. The milestone marks another sign of accelerating competition in advanced AI platforms.
Sentiment also improved after regulatory filings confirmed that Warren Buffett’s Berkshire Hathaway accumulated roughly $4.3 billion worth of Alphabet shares. The investment boosted confidence in the company’s long-term AI strategy and earnings trajectory, with traders viewing the move as a rare endorsement from a traditionally cautious buyer of tech stocks.
Analysts say the combination of product momentum and high-profile institutional support helped fuel heavy trading volume and contributed to the stock’s breakout. Market watchers now expect volatility to remain elevated as Alphabet integrates Gemini 3 across its core services.
