The S&P 500 index has gained 15.8% this year, with one-third of it attributed to Nvidia's stock, which has risen 156% year-to-date. However, not all AI-related stocks are performing well, with Upstart, Snowflake, and Lemonade down 39%, 29%, and 4%, respectively. To mitigate risk, considering investing in an AI-focused exchange-traded fund (ETF) like the Global X Artificial Intelligence.