Since 1926, only 11 companies have ranked #1 by market capitalization; Amazon is the latest. Firms that become #1 remain in that position for an average of about 15 months and outperform the market by an average of 48 percentage points over the five years leading up to becoming #1. The other ten firms that have been #1: Microsoft, Apple, Exxon Mobil, GE, Walmart, Altria, IBM, DuPont, GM and AT&T.