Moreover, the core of his strategy is fairly simple: Buy stocks and hold them for the long haul. Here are two Buffett stocks in that industry to buy hand over fist in the month of October. A card giant with pricing powerThe second-largest position in the Berkshire Hathaway stock portfolio is American Express (AXP -1.03%). The conglomerate owns more than 20% of this dominant player in the premium credit card sector. For decades, American Express has catered to wealthier clients with a variety of credit and charge cards for consumers and businesses.