Here is Gunner’s latest Gann chart.  A link to the commentary is here

http://www.gunner24.com/newsletter-archive/october-2017/15102017/
Essentially it means a grind higher should result in a major top around 6725 in the April/May 2018 time frame.

If the market corrects now and October closes under 5750 then I would take that as confirmation that the high is in.

That would mean sub 4800 in April 2018 would likely be the next major low