Chipmaker Nvidia is replacing Tesla as Wall Street's most traded stock, adding to its prominence after becoming the third-most valuable U.S. company and showing more evidence of how central AI-related bets have become to investors. Nvidia's outsized representation in day-to-day stock trading could leave investors more vulnerable should the chipmaker's revenue growth fail to meet investors' high expectations and puncture a Wall Street rally that has been fueled by euphoria about artificial intelligence. The Santa Clara, California chipmaker's quarterly report on Wednesday will be one of Wall Street's most watched events of the week...

Even though Tesla shares are well off their peak, investors are optimistic about the future...