Here's those charts again that I discussed back in early February when the whole initial hard correction wave A was unfolding.  What I stated at the time was that if this is still a bull market, hard sharp corrections that were greater then 10% always resulted in a retest of the lows or minor new lows, in either a simple ABC correction or a complex ABCXABC type of correction.  What happens is that if a correction is too strong (generally over 10%, it damages the mass psyche of the market enough that it needs time to heal.  This negative impact on the psyche generally needs either an ABC or a larger more complex ABCXABC correction that takes more time to unfold.  Time heals basically.  Market corrections that are swift and fast but not too deep, can simply V-Bottom i.e. corrections less than 10% from what I've observed. 

I discussed that since the correction in early Feb was about 12.5% that it means that the odds were very high that any decent rally after the hard sell off in early Feb would ultimately come back to retest the lows or make slight new lows.  Again either an ABC or more complex, which is now unfolding in at least that wave C.

Here's a collection of charts that I showed back in early Feb showing past corrections that were over 10%, each one of them needed at least an ABC or something more complex in in order to give more time to heal the market psyche.  I've listed the charts below along with a description.  

$SPX - Chart Link- this correction from the highs was early in the bull market and thus was going to be some sort of ABC correction regardless. The correction resulted in the famous 'flash crash' and was large enough that the damage needed time to heal, which is why it resulted in a long ABC complex correction that made slight new lows on wave C. 

$SPX - Chart Link- this is the very large and devastating 2011 correction.  This was still fairly early in the bull market however many thought that it was the start of a bear market because it resulted in about a 22% correction from the highs to the lows (MUCH strong that anything we see now).  This correction was so deep and hurt the market psyche so much that it needed months to heal in an ABCXABC complex correction

$SPX - Chart Link- this one is from 1998 and not part of this bull market, however included it because it was also a hard sharp correction in a bull market that needed an ABC that made slight new lows for ultimately a 21% market correction.

$SPX - Chart Link- this shows the hard corrections of Aug 2015 and Jan/Feb 2016.  Both corrections resulted in a simple ABC correction that both resulted in a test of the A lows or slight new lows before they were over.

$SPX - Chart Link- 2014 correction, this correction was less than 10%, and thus not large enough to damage the bull market psyche, thus it ended being a V bottom, No ABC. However had the correction been much larger then it would have damaged the mass psyche enough that it wouldn't have recovered so quickly and would have did what the other corrections above show.

Here's a link to my Feb 11th weekend newsletter where I discuss in writing  in the table of contents where I said after a decent rally I would expect a retest of the lows again or slight new lows, and of course I show these same exact charts, have a look.  Again I'm not showing this all to say I told you so, but to show that it's what we originally talked about back then is unfolding.  And it's a good education about how markets need time to heal after very strong corrections, typically over 10%, and why you don't see V bottoms after very strong corrections, as the market needs time to heal, which is why you see ABC or complex corrections unfold to give the time needed to heal the mass psyche.  Markets trade on emotion, and that's what we are trying to analyze with technical analysis.

I hope this gives a nice overview.  Again I discussed this a lot back in Feb after that initial leg down occurred and why I thought a retest of the lows was likely going to happen, and now we are there