Based on our time count, wave count and Fib level retracement it very likely the wave 4 up from the crash wave 3 down on August 24th has now been completed last Thursday at the FOMC meeting.
So now I think we are starting the first series of waves down to make the final 5th wave down that should end around the first week of October.
Since we are probably going down in a group of ABC waves, with some having 5 waves inside them we basically just want to look for the wave 3's and C's to short. The FOMC high and further drop into Friday's low was likely some kind of wave 1 (or A) inside a larger wave A... still inside our larger %th wave that again should end in early October with a lower low then the 1867 SPX low and this 1831 futures low by a small amount and making the SPX low about equal it. The futures and SPX cash are currently only about 10 points difference. So if we hit 1800 on the futures we could hit 1810 on the SPX cash. I don't know the low coming but it shouldn't be below 1800 I don't think. For the short term though we are just looking at the wave by wave action to trade it and make some money.
Wave 1 or A down from 2010 FOMC high to 1940 after hours Friday low.
So from what I'm seeing today (Monday September 21st, 2015) the best spot to short at should come Tuesday. The VIX has broken out of its falling wedge pattern and a back test of the trend line it busted thorough is common. Once it back test's it with a higher low (around 19.20 around now) it will act as a springboard and go up again... which means the SPX will go down.