Tim Cook has stepped down as CEO this week, passing leadership to John Ternus, who previously led Apple's hardware division. The transition comes with an immediate test: Ternus faces an iPhone event and major product launch within his first days as CEO.

Cook is not leaving the company entirely. He is staying on as Executive Chairman, though his focus is shifting to policy matters rather than day-to-day operations. In his first memo as CEO, Ternus promised a "huge launch next week," setting an ambitious tone for his leadership.