Tim Cook’s 15-year Apple legacy: From Steve Jobs’s successor to $4 trillion giant

Tim Cook is stepping down as Apple CEO after nearly 15 years at the helm. He will move into the executive chairman role, while John Ternus, head of Apple’s hardware division, will take charge of daily operations from 1 September.

Cook became CEO in August 2011, just before Steve Jobs’s death, and succeeded one of the most influential founders in the technology industry.

Cook built a very different Apple from the one Jobs left behind. His tenure was defined less by breakthroughs and more by scale, operational discipline, services, supply chain control and greater monetization of Apple’s huge device base. This approach made Apple one of the world’s most valuable companies, but leaves Ternus with major challenges around China, regulators and artificial intelligence.

From Steve Jobs’ successor to Apple’s growth architect

Cook’s greatest success was the expansion of the iPhone business. During his tenure, Apple sold approximately 3.1 billion iPhones, according to International Data Corporation (IDC) data.

Apple’s stock also delivered exceptional returns. The Financial Times reports it has more than tripled since Cook’s arrival, with over $1 trillion to shareholders through buybacks and dividends.

The tech giant’s workforce grew from about 60,000 in 2011 to roughly 166,000 today, while its retail footprint expanded to more than 500 stores worldwide.

Turning Apple into a services machine

One of Cook’s most important moves was reducing Apple’s reliance on hardware sales. The App Store, Apple Music, iCloud and Apple Pay became central to business. The Financial Times estimates Apple now has 1.5 billion paying subscribers.

Apple also boasts that more than 2.5 billion Apple devices are in use globally, a massive installed base that has become one of its biggest competitive strengths.

Supply chain became Tim Cook’s signature

Cook’s background in operations shaped his leadership. He built an efficient manufacturing and supply chain network, with China at its core.

This model allowed Apple to produce hundreds of millions of devices while maintaining margins. Operating margins improved significantly under his tenure.

But the same system backfired when US-China tensions escalated. The Financial Times reported that about 90% of Apple’s suppliers were partly based in China or Taiwan. Apple’s market value fell by $638 billion over three days in April 2025 after US President Donald Trump imposed sweeping tariffs. Cook responded by promoting diversification while sustaining ties with China.

Five new hardware categories in 15 years

Cook’s influence on Apple’s product lineup was less dramatic than Jobs’s. The iPhone, Mac and iPad remained core, but five new hardware categories emerged: AirTag and Vision Pro, Apple Watch, AirPods and HomePod.

The Watch and AirPods became runaway successes. Apple ended its long-running car project in 2024, while HomePod and Vision Pro remained niche products.

Cook’s less visible hardware legacy was Apple’s move to design its own chips. The transition to Apple Silicon boosted performance and strengthened Apple’s control over its products.

Tim Cook leaves behind a $4 trillion giant

Cook leaves behind a $4 trillion Apple built on scale, supply‑chain mastery and services growth. As he moves to the executive chairman role, Ternus inherits both the company’s record valuation and some of its toughest strategic questions — from innovation and China dependence to regulatory scrutiny and AI.