US stock market’s concentration hits all-time high. Is that a problem for crypto?

The US stock market is showing off a new trick: putting almost all its eggs in a tiny basket. Right now, just 26 stocks account for half the entire value of the S&P 500 index. This is a straight-up historical anomaly.

The previous number was 36 stocks at the end of 2023, which already felt low. Now, it’s the lowest since at least 1980 and probably since the index was created in 1957. Records like this don’t get broken without raising some serious questions.

The tech sector is running the show. Nvidia, Microsoft, and a small gang of other mega-cap tech giants are in control. The top 10 stocks alone now make up 37.3% of the S&P 500. Howard Silverblatt of S&P Dow Jones Indices confirmed this is a modern-day record. This level of concentration has pushed diversification—supposedly the bedrock of investment strategies—into myth territory.

Nvidia is the S&P 500’s top-performing stock

Torsten Sløk, Apollo’s chief economist, calls this setup a “diversification illusion.” On paper, buying into the S&P 500 should mean you’re spreading your investment across 500 different companies.

But the reality is different. “It’s basically Nvidia in disguise,” he said. And Nvidia’s performance, largely driven by its dominance in AI, is making or breaking portfolios.

While Nvidia gets a lot of attention, this isn’t a one-off issue. Two key factors explain this concentration: insane profit growth by mega-cap companies over the last decade and their rising valuations.

The real concern might not even be the concentration itself but the forces behind it: profits that keep flowing to the same companies and their market valuations that keep climbing.

Crypto breaks free—or does it?

While the stock market clings to its few favorites, crypto seems to be quietly leaving their toxic relationship. For years, Bitcoin and tech stocks moved in sync. But as of early 2025, the tides may be turning.

The crypto market is throwing off hints of independence from traditional market trends, though it’s not a clean break yet. Trading at $102,000, Bitcoin is up more than 10% from its late December price of $92,000 right now. Altcoins like Ethereum and Dogecoin are seeing even bigger gains—roughly 13% since January 1.

Analysts are watching Bitcoin’s price moves closely. As president Donald Trump’s inauguration approaches, there’s a strong chance Bitcoin could break new records if its upward trend holds steady. The early signs of decoupling from the S&P 500 give crypto enthusiasts a reason to stay optimistic.

But not everyone is convinced. Crypto has long been compared to high-leverage tech stocks, and its volatility still keeps it in risky territory. A big factor behind the optimism in crypto is politics. Trump’s return to the White House has crypto excited. He has already started enacting some pro-crypto rules.

The economic backdrop also matters. Credit availability is on the rise, job growth is strong, and a weaker US dollar is pushing investors toward riskier assets. These conditions create a perfect storm for Bitcoin to shine.