The S&P 500 is made up of 11 distinct sectors, though just a few dominate it. The tech industry today makes up 32% of the entire value of the stock index — $20 trillion out of a total $63 trillion.

Peter Oppenheimer—who correctly called U.S. underperformance and the global rotation—now sees elevated risk of a correction.

There is nothing more sickening than seeing unrealized gains in the stock market melt away because you thought about hedging but didn't. Many investors have decided that now is the time to avoid that ...