I rated Tim Cook a 'loser' in 2013. He proved me — and Silicon Valley — wrong.

Source: Business Insider

Tim Cook (left) and CEO Steve Jobs remove microphones on a stage at Apple headquarters in Silicon Valley in 2010. REUTERS/Kim WhiteAfter Apple cofounder Steve Jobs died, many questioned whether Tim Cook would succeed. Cook took Apple to new heights, adding more than $3 trillion in market value — way more than Jobs.