The stock market’s impressive performance in 2023, with a staggering 24% return for the S&P 500 Index ($SPX), might have defied expectations – but stocks are still on the rise in 2024, and many of the top performers have been mega-cap stocks. Those are the big guns with market caps over $200 billion, and these household names tend to be very well-represented in benchmark equity indexes like the S&P 500 and the Nasdaq-100 Index ($IUXX). Some market watchers have grown skeptical about how much upside is left for some of these outperforming mega-caps, and it’s a fair question, particularly as for…