Investing.com -- Apple (NASDAQ: AAPL) shares fell over 1% after the market close on Monday following the company’s announcement that Tim Cook will transition to executive chairman and John Ternus will become the next chief executive officer, effective September 1, 2026.

The leadership change, which was unanimously approved by Apple’s board of directors, came as a surprise to investors. Cook will continue as CEO through the summer to work closely with Ternus on the transition.

Ternus, currently senior vice president of Hardware Engineering, joined Apple’s product design team in 2001 and became a vice president of Hardware Engineering in 2013. He joined the executive team in 2021 and has overseen hardware engineering work across multiple product lines, including iPad, AirPods, iPhone, Mac, and Apple Watch.

As executive chairman, Cook will assist with certain aspects of the company, including engaging with policymakers around the world. Arthur Levinson, who has been Apple’s non-executive chairman for the past 15 years, will become lead independent director on September 1, 2026. Ternus will join the board of directors on the same date.

Cook became CEO in 2011 and has overseen Apple’s growth from a market capitalization of approximately $350 billion to $4 trillion, representing a more than 1,000% increase. Yearly revenue has nearly quadrupled from $108 billion in fiscal year 2011 to more than $416 billion in fiscal year 2025.

During Ternus’s tenure, he was instrumental in the introduction of multiple new product lines and led the company’s focus on reliability and durability. He holds a bachelor’s degree in Mechanical Engineering from the University of Pennsylvania.