Pisani: Here's what could take S&P 500 to new high

We're here again, knocking on the door of historic highs in the . It's like Groundhog Day. Since hitting a historic closing high of 2,130 in May 2015, we came close to passing it in the next two months and in November, then in April, and now this week.

Will it ever happen?

In exclusive content for Pro subscribers, I describe the deciding factors that could take the S&P to a new high.