Apple shares hit an intraday record high of $182.88 on Monday, putting Apple's market value just above $3 trillion. The Silicon Valley company's shares ended the day up 2.5%, with its market capitalization at $2.99 trillion. Apple shares have risen about 5,800% since co-founder and former chief executive Steve Jobs unveiled the first iPhone in 2007. Some investors worry Apple is hitting the limits of how much it can expand its user base and how much cash it can squeeze from each user.

Sales surged nearly 30% to more than $83 billion in Apple's fall quarter, which ended in September. Microsoft is now worth about $2.5 trillion and Google owner Alphabet's market value is right around $2 trillion. Still giant but further behind are Amazon (AMZN) and Tesla (TSLA).