Over the past 10 days, the average stock in the S&P 500 has undergone increased volatility. At the same time, the correlation among stocks in the index has declined. This is highly unusual. Likely due to a rotation into smaller stocks, similar behavior has led to further gains in smaller stocks.; The energy sector is trying to change it long-term trend, with the S&P 500 Energy index closing in on its 200-day average for the first time in almost a year, and after suffering its worst-ever spread against that average.

---