The tech-heavy Nasdaq closed higher on Tuesday, leading gains on Wall Street amid investor excitement about artificial intelligence before earnings reports from megacap technology companies Alphabet, (GOOGLE.O) and Microsoft (MSFT.O) after the bell. Both Microsoft and Alphabet have launched an array of AI products since OpenAI, backed by Microsoft, released ChatGPT in late 2022. Investors expect the new products will help tech giants offset a slowdown in their cloud businesses.