Interestingly, NVDA took a back seat to other mega-caps in December and was not an important factor this time. NVDA shares fell approximately 2.9% in December.
Instead, three other mega-cap stocks were particularly relevant this month.
Broadcom (AVGO), a leading player in semiconductors which now has a $1 trillion market cap, advanced 43%. Tesla (TSLA), which has a $1.3 trillion market cap, rose 17%. Alphabet (GOOGL), the parent company of Google with a $2.3 trillion market cap, rose 12%.
All three stocks rallied on the heels of positive news flow related to AI growth. In other words, there were company-specific catalysts that drove upside in these stocks.
Since these three stocks now collectively represent more than 8% of the index, their strong performance had a material effect on total index returns.
Concentration within the S&P 500 Index has reached historically extreme levels. This has many investors concerned, in part because the last time we saw this was right before the dot com bubble burst.
The top 10 holdings of the S&P 500 currently represent nearly 40% of the total index; this figure was closer to 30% at the peak of the dot com era in 1999. The top 20 holdings of the 500 stock index represent almost 50% of the total value.
All but one of the top 10 holdings within the S&P 500 are technology or technology platform stocks. The lone exception is Warren Buffett’s conglomerate Berkshire Hathaway (BRK/B), which ranks tenth.
Buffett is known as an old school value investor, but ironically, his large and highly successful investments in tech stocks like AAPL are a major reason BRK/B is now a top 10 name in the S&P 500.
Without diving into the controversy around whether or not we are in bubble territory when it comes to these mega-cap tech names, we continue to believe most stock market investors have plenty of exposure to them through index funds and active funds that track major indices.
We therefore continue to believe stock pickers should focus their attention on opportunities outside these widely held names, many of which do have quite rich valuations.
What happened to the rest of the market?
As a reminder, November produced a very strong month for stocks in the wake of Trump’s victory and the Republican sweep of Congress.
In November, we saw strong positive performances across the market. The S&P 500 returned 5.9%. The Russell 2000 Index, which tracks small-cap stocks, advanced 11%.
This post-election optimism shifted abruptly on December 19, after the Federal Reserve meeting. Although the Fed did cut the Fed funds rate by 25 basis points, which was widely expected, the anticipated trajectory of future rate cuts changed.
Official projections for the Fed funds rate by end of 2025 were raised approximately half a percent, from 3.4% to 3.9%.
The prospect of potentially stickier inflation and tighter monetary policy dampened market sentiment, just as much of the professional investment industry was preparing for year end and time off for the holidays.
Over the course of December, the yield on the 10-year Treasury rose back to the 4.6% range, just about hitting April 2024 peak levels, after having started the month around 4.2%.
Concerns around interest rates led to widespread selling pressure. This was felt across most sectors.