All investments involve some degree of risk, especially investments in the stock market. That's why diversification is a bedrock principle of investing. Diversification simply means spreading out risk by owning several different stocks that might perform independently from each other.

Market breadth has been extremely strong. Both breadth oscillators are on buy signals and are in deeply overbought territory. It is fine for these oscillators to be overbought when the S&P 500 is beginning a new leg upward. They could probably withstand two and maybe even three days of negative breadth and still maintain their buy signals.

Powell’s post-meeting remarks on May 1 appear to be easing financial conditions this month. Over much of this month, stock investors have enjoyed a rally, helped by easing monthly consumer-price gains for April and the Federal Reserve’s willingness to ...