Arm Holdings (ARM 2.95%) is one of the best-performing artificial intelligence (AI) stocks of the last year, trading up 119%.However, Arm doesn't make money the way most semiconductor stocks do. Instead of selling its products directly to customers, the company licenses its technology, primarily its CPU (central processing unit) architecture to partners like Nvidia and Apple. Then it collects royalties when the products containing those designs are sold, so licenses and royalties make up its two sources of ...