It's not that the stock market hasn't moved. We've seen several new all-time highs, and the S&P 500 is up by 1.6% in July so far. While 1.6% might not seem like much, it works out to more than 20% annualized. If your portfolio made 1.6% every month, you'd be very happy.

U.S. stocks are trading near record highs heading into the thick of the second-quarter earnings season, but with markets historically expensive and reliant on the performance of tech companies, some investors are starting to embrace a more cautious outlook.