Here are the instances in the past 2 years showing what happened when the 21MA of the CCI dipped from positive to negative. Before I begin, a little disclaimer: Occurrences are quite low @ 6 so take this with a grain of salt! I did go through data back to early 2008 (not shown here), and they are all similar to charts below.
Everytime, the market put in a short term bottom within 0-4 days and bounced significantly, including the instances not shown. TNA returned 10% to 28% from the bottom holding for 5 days. The exception was chart 2 below where it topped on day 4 and dropped hard day 5. XIV did ok, but if we get into backwardation like in Aug'11, it will under-perform. See pic 3. For this reason, my first few long purchases this week will be XIV, but will switch to TNA on Weds/Thurs if we keep dropping. Most of these bottoms occurred below the gray shaded bollinger band. I would like to see something similar this time before I get heavily long. I'm guessing our bottom could come around 1400 before the big bounce. I will get very aggressive down there. Otherwise, if we go up this week, like pic 2 below, I will unload my current 25% long position and begin building shorts this week.
This is my trading plan for the next 1.5 weeks and I will likely be disregarding my signals. We'll see how it goes, though. See you tomorrow.