On January 13th, MozCast measured significant algorithm flux lasting about three days (the dotted line shows the 30-day average prior to the 13th, which is consistent with historical averages.
That same day, Google announced the release of a core update dubbed the January 2020 Core Update (in line with their recent naming conventions)…
Ultimately, the impact of core updates gives us clues about Google’s broader intent and how best to align with that intent.
Look at sites that performed well and try to understand how they might be serving their core audiences. If you lost rankings, are they rankings that matter? Was your content really a match to the intent of those searchers?