It finally happened. Small caps started running while the S&P 500 kept leaning on the same handful of giants. As of early June, US small caps were up roughly 16% year to date versus about 8% for the S&P 500, a rare reversal of the post-2020 playbook (BMO Insights).
Then, near the end of the month, the Russell 2000 printed 3,007.86 on June 25, 2026, right as the annual reconstitution forced billions in index trades to settle (Reuters).
You could feel the tension: can the market keep leaning on the same mega caps when breadth is finally waking up?
Here’s the setup. The S&P 500 has been extremely top heavy. Multiple June snapshots put the top‑10 names at roughly 37–38% of the index by weight (MarketXLS). That’s a lot of market risk stuffed into a small group of tickers. At the same time, small caps quietly started to outperform into mid-year. And June’s Russell shake-up added fuel.
When leadership narrows and then small caps start to catch a bid, the ma
We współpracy z: https://cryptodaily.co.uk/2026/06/sp500-small-cap-divergence-russell-2000-strength
