Percent down from recent high to closing low.
-7.4% October 2014
-4.9% December 2014
-12.2% August 2015
-11.9% January 2016
-5.5% June 27 2016 7:20 am PT
I don't make any predictions how far this decline will go. The markets had been taking a more defensive structure starting months before this sell off. Bonds started climbing a year ago. Utilities started up six months ago.
Note that in October 2014 the intraday low was -9.4%. January 2016 intraday low was -14.1%.
Volatility has been going on since late 2014 and is expected to continue. The trouble with these down drafts is that first it takes a down draft before the market goes even lower.