What relationship was highlighted in 2015 between economic surprises and the 6-month percentage change in the S\&P 500? The economy had overall positive surprises throughout the year, and the S\&P 500 had a strong rally and finished much higher. The economy had overall negative surprises throughout the year, and the S\&P 500 increased in the early part of the year but finished slightly lower. The economy had overall negative surprises throughout the year, but the S\&P 500 , had a strong rally and finished much higher. Click to open/close chart