Key PointsThe S&P 500 is trading at its second-highest CAPE ratio ever -- a reason for some caution.Buffett has credited a few, smartly executed trades with driving Berkshire Hathaway's gains.10 stocks we like better than S&P 500 Index › Artificial intelligence (AI) stocks continue to thrive, and they're a major force behind the market's ascent this year. The S&P 500 (SNPINDEX: ^GSPC) is up 7% year to date, and the tech-heavy Nasdaq-100 is up 15…