Microsoft is the world's most valuable company with a market cap of $3.15 trillion. Nvidia has overtaken Apple as the second most valuable company with a $3.011 trillion market cap. Google parent Alphabet ($2.177 trillion) is the 4th most valuable company. Alphabet is followed by Amazon, Saudi Aramco, Meta, Berkshire Hathaway, TSMC and Eli Lilly, according to the website companiesmarketcap.com.