Time to time Google gives an update in their algorithms When algorithm updates ranking definitely, fluctuations then we use various SEO tools as Semrush etc to check that how our page rankings are fluctuating.
Penguin is something common with Panda, it evaluates websites for a different factor as their link profiles. Now it has taken action to remove bad links.
Penguin now runs in real time. Penguin 4.0 impact individual pages to entire domains. For a better result in SERP page, you must make strong backlinks, quality type link and most easiest way to do a better recovery scan your site with Backlink Quality Check tool.
If you want Best SEO company than always active in google algorithm update and follow them in your seo work. it definitely help you to reach you goals.