The S&P 500 soared more than 7 percent in the third quarter, which ended on Friday. That's the strongest quarter for the S&P since the fourth quarter of 2013. The Dow spiked more than 2,100 points, or 9 percent, in the quarter.
Health care was the best-performing sector of the third quarter, surging 14.1 percent, its best quarterly gain since the first quarter of 2013. Industrials and tech, meanwhile, rose 9.7 percent and 8.5 percent.
The strong third quarter on Wall Street could also be a good omen for the rest of the year. When the S&P 500 rises in the third quarter, it has advanced an average of 3.8 percent in the fourth quarter of all years since 1945, according to CFRA Research. In midterm election years, the S&P 500 rallies an average of 7.1 percent in the fourth quarter following a third-quarter gain.