Are we in the late stages of a bull market—that time when the market suddenly takes off like a rocket for no apparent reason? Over the last eight years, the S&P 500 index has returned more than 300%. But the tail end of this run seems to have accelerated the trend. The first quarter of 2017 provided the highest returns for U.S. large-cap stocks since the last three months of 2013. The Nasdaq index has booked its 21st record close of the year so far, and the indices have recorded a 30% rise over the past six quarters, marking the fastest advance since 2006.

Download