Days ago Google had officially announced a Penguin v4.0 algorithm, after two years ago they had released Penguin v3.0 in October 2014, and the first launched at 2012 ago. Google said Penguin v4.0 algorithm are part of their core algorithm which we knew that Google Algorithm Core relies upon on more than "200 ranking signals." The signals including things like keywords at the content, up to date content, PageRank, and much more.
Google said after some of testing and development, now they have release out the Penguin algorithm and it available in all languages, the main point of updates is:
If Penguin v3.0 hits your sites and still no sign of recovery even on small hints, then maybe your sites still affected so give more couple of weeks to Penguin v4.0 to roll out completely, and re-check your analytics again if your sites show sign of recovery.