While Buffett hasn't had a problem finding opportunities to invest capital throughout most of his tenure, the value-focused investor has found fewer investments to his liking in recent years. Berkshire has sold more stocks than it bought for its equity portfolio in each of the last dozen quarters. These stock sales, which have included trimming its Apple position, have contributed to the rise in its cash position. Meanwhile, Buffett hasn't found too many acquisition opportunities either. Berkshire's recentl ...