Top 10 Companies in USA by Market Cap (2021) 

Microsoft Corporation. 2,268 Billion US $ 

ALPHABET. 1,933 Billion US $ 

Amazon 1,757 Billion US $ 

Facebook. 1,069 Billion US $ 

Tesla Inc. 736 Billion US $ 

Berkshire Hathaway. 646 Billion US $ 

Nvidia Corporation. 557 Billion US $