Is This Warren Buffett's Favorite Stock? (Hint: It's Not Apple)
There is one stock he has never sold since buying in 1991, though: American Express ( AXP -0.20%). Buffett owns over 20% of the credit card issuer and bank, making it the second-largest position in the Berkshire Hathaway portfolio. The position trades at a value of $40 billion as of this writing.