Google’s newest version of one of their big algorithms, Panda 4.2, was released on July 18, 2015. Everything seemed okay at first, but around August 14th, there was some speculation that the Panda 4.2 update was reversed or greatly changed.
Even though we knew that it would take several months for Panda 4.2 to roll out, and because of that, we would find that more and more pages on your site will be updated with new Panda scores. But around August 14th, there was a number of those webmasters who would begin seeing their improved scores completely wiped out overnight.
Here is a graph that was shared by Barry Schwartz from his own personal recovery on the Search Engine Roundtable:
As you can see from Barry’s graph, the organic traffic he was experiencing was starting to climb after the release of Panda 4.2, but then suddenly went back to the way they were after August 14th.
At this point, Google was asked what was going on, and at this point, Google hasn’t commented on the matter.