Artificial intelligence (AI) could create trillions of dollars in economic activity, and that spells opportunity for investors.At the beginning of 2023, semiconductor giant Nvidia (NVDA 0.81%) was a $360 billion company. Its fortunes quickly changed when OpenAI and its artificial intelligence (AI)-powered chatbot, ChatGPT, captivated investors.ChatGPT's ability to accurately answer complex questions and generate text and computer code on command sent some of the world's largest tech giants clamoring to buy ...