Wall Street analysts are bullish on Nvidia and bearish on Palantir.Consultancy PwC estimates artificial intelligence (AI) will contribute more than $15 trillion to the global economy by 2030. Investors hoping to benefit are piling into AI stocks, and Nvidia (NVDA -0.03%) and Palantir Technologies (PLTR 1.95%) have been two of the most popular choices.In the last two years, Nvidia shares surged 728%, and Palantir shares advanced 348%. But Wall Street analysts expect the stocks to move in opposite directions ...