Apple hit a market cap of $1 trillion on Thursday, becoming the first publicly traded U.S. company to reach the historic record.

"Steve founded Apple on the belief that the power of human creativity can solve even the biggest challenges — and that the people who are crazy enough to think they can change the world are the ones who do," Apple CEO Tim Cook said in an email to employees on Thursday. "Just as Steve always did in moments like this, we should all look forward to Apple's bright future and the great work we'll do together."