Tech's biggest companies just wrapped up a huge year. The seven most valuable U.S. technology companies Apple, Microsoft, Amazon, Alphabet, Facebook, Tesla and Nvidia " picked up a combined $3.4 trillion in market cap in 2020, powering through a global pandemic and broader economic crisis. Between continued optimism over iPhone sales, Microsoft's growing Teams collaboration product, Amazon's ongoing control of e-commerce and the strength of Google and Facebook's online ad duopoly, Big Tech was neither slowed by Covid-19 nor the rising number of investigations into its dominance. By far the biggest increase in market cap went to Apple, which jumped by almost $1 trillion in value, thanks to its stock climbing 81%. Amazon, which benefited from growth in its consumer and cloud-computing business, rose by $710 billion. Microsoft picked up $480 billion, while Alphabet gained $268 billion and Facebook $193 billion. The gains are clearly reflected in the ranks of the richest people. Amazon's Jeff Bezos is the wealthiest person in the world, followed by Tesla's Elon Musk and Microsoft co-founder Bill Gates. Facebook CEO Mark Zuckerberg is fifth. Also in the top 10 are Google founders Larry Page and Sergey Brin and Microsoft ex-CEO Steve Ballmer.