Ternus Takes Reins as Apple CEO, Cook Steps Down

John Ternus has taken over as CEO of Apple, replacing Tim Cook who stepped down after 15 years at the helm. Ternus, who first joined Apple in 2001, was named senior vice president of hardware engineering before his new role. The company's valuation stands at $4.6 trillion.

Cook succeeded Steve Jobs in August 2011 and oversaw a significant growth in Apple's stock value, increasing from $13 to over $320 during his tenure.

Ternus will make his first public appearance as CEO at Apple's annual product launch event on September 9. The company's stock rallied nearly 3 percent following news of the succession.