Market-cap weighting has left many investors overly exposed to a handful of mega-cap winners, prompting calls for diversification into mid-cap stocks that offer better value and lower volatility.
Nvidia is cited as a mega-cap whose high valuation inflates the index, with potential downside in a correction.
The article discusses the S&P 500's elevated valuation driven by mega-caps while highlighting mid-cap opportunities.
Microsoft is similarly mentioned as a large-cap tech name contributing to index concentration and valuation concerns.
Portfolio manager Josh Wein warns that the S&P 500's 21-times-earnings valuation is heavily skewed by mega-cap tech giants like Nvidia and Microsoft. He suggests that investors review their portfolios for over-concentration and consider mid-cap stocks, which currently trade at more modest multiples of 16 to 16.5 times earnings.
The S&P 500 is market-cap-weighted, meaning the largest companies have a disproportionate impact on the index's total valuation, often masking more modest valuations among smaller constituents.
Heavy concentration in mega-caps creates vulnerability to corrections, as these stocks are often priced for perfection and can fall the hardest during market pullbacks.