Do top-heavy markets eventually spread out?
Many investors have experienced extraordinary stock market gains over the past two years, with the S&P 500 up 26.3% in 2023 and another 25% in 2024. For perspective, the long-term average annual return for the S&P 500 index is 9.7%.
Even more impressive, the last time the S&P 500 saw back-to-back 25%+ gains was 1997-1998.
One downside: Those big returns in ’23 and ’24 were driven almost entirely by a small handful of stocks. Collectively, the Magnificent 7 (Alphabet, Amazon, Apple, Meta, Microsoft, Nvidia, and Tesla) soared nearly 250% over the past two years, fueled by investors’ hope that AI will transform how the world does business. The index’s 10 largest companies rose 129% (see the chart).
In stark contrast, the return of the S&P 500 equal weight index over this period was “just” 29%—a gap of 100 percentage points compared to the top 10 largest stocks.
Concentration of S&P 500 Returns, 2023 – 2024
Source: Bloomberg, calculations by Horizon Investments, data as of 12/31/2024. Indices are unmanaged and do not have fees or expense charges, both of which would lower returns. It is not possible to invest directly in an index.
Such extreme return concentration may cause some investors with well-diversified portfolios to feel left behind, even after benefiting from the S&P 500’s historically strong performance. In today’s environment, we believe this is hardly the first time market returns have been exceedingly top-heavy. For example, the “nifty 50” stocks of the 1960s and early 1970s drove the broader market higher for years before suffering an extended period of dramatic and unexpected underperformance. Similarly, red-hot tech stocks in the late 1990s hit a wall in the early 2000s.
The upshot: Maintaining a well-diversified portfolio is essential as the market is inherently unpredictable. Diversified investment strategies that include a wide range of individual stocks from multiple market sectors play a key role in goals-based portfolios seeking to strike a balance between risk and potential reward—especially for investors in (or soon to be in) retirement.