Economist Ed Yardeni suggests generative AI could spark a new 'Roaring 20s' era despite ongoing pandemic and economic challenges. The S&P 500 and Nasdaq have surged in 2023 due to generative AI innovations, with potential for sustained growth. Leading tech companies like Microsoft and Alphabet are embracing generative AI, while small-cap options like UiPath, Domo, and Lemonade offer investment potential. The AI boom could reshape industries and lead to significant market expansion, though caution is advised due to potential volatility.