Apple CEO Tim Cook is stepping down from his role after a 15-year tenure that saw the company achieve several historic milestones, including becoming the first publicly traded U.S. company to reach a $1 trillion market capitalization and later surpassing $2 trillion in 2020, $3 trillion in 2022, and $4 trillion in October 2025. Cook announced in April that he would step down at the end of August, but he will remain with Apple as executive chairman. John Ternus, previously Apple's senior vice president of hardware engineering, will succeed Cook as CEO [1].
Cook began his career at Apple in 1998 after being recruited by co-founder Steve Jobs and became CEO in August 2011, six weeks before Jobs' death. Under Cook's leadership, Apple expanded its product and service offerings, launching the Apple Watch and Apple Pay in 2014, Apple Music in 2015, AirPods in 2016, and Apple TV+ and Apple Card in 2019. These moves helped Apple build a broader consumer tech ecosystem beyond its core MacBook, iPhone, and iPad products [1].
During Cook's tenure, Apple frequently competed with ExxonMobil, Nvidia, and Microsoft for the title of the most valuable publicly traded U.S. company, with the top spot regularly changing hands among these firms. In July 2026, Apple briefly overtook Nvidia for the largest market capitalization [1].
Cook expressed his gratitude to Apple employees in a memo on his final day, emphasizing the company's collaborative culture and the collective achievements made during his leadership. He stated, 'As you know, I am not leaving Apple. But I am stepping away from a role that I have loved deeply,' and reflected on the company's ability to 'leave our dent in the universe' as described by Steve Jobs [1].
CONCLUSION
Tim Cook's departure as Apple CEO marks the end of a transformative era, with the company reaching unprecedented market valuations and expanding its product ecosystem under his leadership. The transition to John Ternus as CEO is a significant leadership change for Apple, but Cook's continued presence as executive chairman suggests continuity. The market impact is high, given Apple's stature and the milestones achieved during Cook's tenure.