The artificial intelligence (AI) industry is still in its infancy, but investors already witnessed its incredible potential to create value. Since the start of 2023, Nvidia's (NVDA -1.68%) market capitalization has grown from $360 billion to $3.3 trillion, almost entirely because of soaring sales of its AI data center chips.But the industry is evolving fast, so picking the long-term winners and losers won't be easy. That's why buying an exchange-traded fund (ETF) that holds several different AI stocks could ...