Alphabet, Google's parent company, has reached a market capitalization of $4 trillion, with its stock price climbing 1.7% to $334.04 per share. This milestone positions Alphabet as the second-largest company globally, surpassing Apple and trailing only NVIDIA. The stock surge was fueled by Apple's decision to use Alphabet's Gemini model for its AI-powered Siri assistant. Alphabet's stock has risen 4.8% this year, building on a 65% increase from the previous year, making it the top performer among the 'Big Seven' tech giants. NVIDIA, Apple, and Microsoft are the only other companies to have surpassed a $4 trillion market cap, with NVIDIA being the sole company to exceed $5 trillion.