In a landmark achievement for the technology sector, Alphabet Inc., the parent company of Google, has soared past a market capitalization of US$4 trillion. This milestone, reached on Monday, places the Silicon Valley giant among an exclusive club of corporate titans, firmly establishing it as a central architect and beneficiary of the ongoing artificial intelligence revolution.
The Drive to a Trillion-Dollar Valuation
The stock climbed as much as 1.7 per cent to US$334.04 during the trading session, pushing its total market value over the historic line. This surge follows a report from CNBC indicating that Apple Inc. selected Alphabet's Gemini AI to power a new, intelligence-enhanced version of its Siri digital assistant. A previous Bloomberg News report in November suggested Apple could pay Alphabet around US$1 billion annually for this AI partnership.
This development is a significant vote of confidence in Alphabet's AI capabilities and marks a pivotal competitive shift. The company recently overtook Apple to become the world's second-most valuable firm, now sitting behind only the AI chip powerhouse, Nvidia Corp.. To date, only Nvidia, Apple, and Microsoft Corp. have breached the US$4 trillion barrier, with Nvidia remaining the sole company to have ever reached a US$5 trillion valuation.
Alphabet's AI Dominance Rewarded by Investors
Alphabet's stock has enjoyed a remarkable run, gaining 4.8 per cent year-to-date in 2026 after an explosive rally of more than 65 per cent in 2025. That performance crowned it the top performer among the so-called "Magnificent Seven" mega-cap stocks. The 2025 surge alone added nearly US$1.5 trillion to the company's market worth, a staggering increase that underscores the rapidly shifting investor sentiment.
Analysts attribute this optimism to Alphabet's perceived dominant positions across key pillars of the AI ecosystem. The company's latest Gemini AI model has received widespread acclaim, helping to alleviate earlier concerns about competition from rivals like OpenAI. Furthermore, its proprietary tensor processing unit (TPU) chips are viewed not just as tools for its own services, but as a potentially major future revenue driver in the competitive AI infrastructure market.
"The company's competitive advantages are not only intact but growing, and no other player has the models, compute, applications, talent, and data to succeed in AI," said Divyaunsh Divatia, a research analyst at Janus Henderson Investors. "It is certainly being seen as a big AI winner, and that strength helps investors feel more comfortable giving it a more-premium valuation than it previously got."
Valuation and the Stamp of Approval
This renewed confidence is reflected in the stock's valuation. Shares now trade at around 28 times estimated earnings, close to their highest level since 2021 and well above their 10-year average of 20.5. This represents a dramatic recovery from a multiple that fell to nearly 14 in mid-2025.
Despite this swelling valuation, Alphabet continues to trade at a slight discount to the overall Magnificent Seven index. The company also received a notable endorsement from a typically tech-wary corner of the investment world. In November, Warren Buffett's Berkshire Hathaway Inc. revealed it had built a stake in Alphabet during the third quarter, a move interpreted as a strong show of confidence from the legendary value investor.
Alphabet's breach of the $4 trillion mark is more than a financial milestone; it is a testament to the company's successful pivot to harness the AI wave. With key partnerships, leading in-house technology, and growing investor belief in its long-term roadmap, Alphabet has solidified its position at the very forefront of the new technological era.
