Apple and Microsoft’s valuation hit $4tn as stock market bubble fears grow

Core Insights - Apple and Microsoft have both surpassed $4 trillion valuations, driven by excitement around artificial intelligence (AI) and robust stock market performance [1][2] - Microsoft shares have increased by 28% in 2025, while Apple shares have risen by 15%, adding approximately $900 billion and $459 billion to their market capitalizations respectively [2] - Concerns about potential market bubbles are emerging, with some analysts noting "frothy areas" in the stock market [2] Company Performance - Microsoft is viewed as more deserving of its high valuation due to its higher growth rate, while Apple faces scrutiny over its innovation and AI strategy [3] - Microsoft announced a new deal with OpenAI, leading to a 4.2% increase in its shares, and is set to take a $135 billion stake in OpenAI, which is valued at $500 billion [3][4][5] - Apple's shares reached a record high of $269.87, becoming the third company to surpass the $4 trillion mark, following Microsoft and Nvidia [6] Product Demand - Strong demand for Apple's latest iPhone models has alleviated concerns regarding its AI advancements, with shares gaining about 13% since the new launches on September 9 [7] - The iPhone constitutes over half of Apple's profit and revenue, indicating that increasing sales can enhance its ecosystem engagement [8]