It's clear that the shine is coming off of some AI stocks, while others remain solid long-term investments.What's happened to the artificial intelligence (AI) rally? It's the question many investors are asking -- and for good reason. Shares of the hottest AI stocks, like Nvidia, cooled off in recent weeks.Nevertheless, we must remember that holding through volatile, choppy markets is integral to the buy-and-hold strategy. Moreover, despite the current pessimism seeping into the market, the AI revolution is ...