The accomplishment is even more impressive considering it has been just two years since Nvidia passed $1 trillion in market cap. Apple and Amazon reached $1 trillion in 2018 and Microsoft followed suit in 2019.

Nvidia (NASDAQ:NVDA) stock was the first-ever company to hit a $4 trillion market cap. As the GPU colossus looks to $5 trillion and beyond, the big question in tech is which company will be second, and in what timeframe will number two be stepping up to the plate?

Once the world's most valuable company, Exxon Mobil now trails AI giants like Nvidia, which recently hit a $4 trillion market cap. Microsoft and Apple also thrive, while Nvidia leads in AI infrastructure.