Apple, Microsoft, and Nvidia Top the List of Largest Companies by Market Cap. Here's the One I'm Buying Now.

Key Points Nvidia's massive growth rate will widen the gap between it and other companies. Apple stock looks overvalued. 10 stocks we like better than Nvidia › At the time of this writing, the three largest companies in the world are Nvidia (NASDAQ: NVDA) at a $5.4 trillion market cap, Apple (NASDAQ: AAPL) at $4.6 trillion, and Alphabet (NASDAQ: GOOG) (NASDAQ: GOOGL) at $4 trillion. There's still a decent gap between Alphabet and fourth-place Microsoft at $3.65 trillion, and an even larger gap to fifth-place Amazon at $2.7 trillion. But of the three largest companies in the world, which one makes the most sense to buy now? I think there's a pretty clear-cut answer, as one stands out above the rest as a buy.