Apple reclaimed the title of the world's most valuable company, overtaking Nvidia as investors grew cautious about the artificial intelligence investment boom. Apple's shares rose 1.2% on Monday, lifting its market capitalization to a record $4.95 trillion. Nvidia fell 5%, reducing its market value to $4.78 trillion, after Bloomberg reported that the cost of insuring its debt against default had risen by a record amount amid concerns over its AI infrastructure commitments. Nvidia had held the title for more than a year after surpassing Microsoft in June 2025, but its forward price-to-earnings multiple fell to 18.2 from 25.5 at the beginning of the year. Apple's shares have outperformed the Nasdaq 100 by 23 percentage points since the beginning of July. Concerns intensified after the Wall Street Journal reported that Nvidia is in talks to provide $250 billion in financing to OpenAI for a data center project in Ohio, which Jefferies viewed as "circular financing." Nvidia also faced pressure after the IPO of Chinese memory chipmaker CXMT triggered a selloff across the semiconductor sector.