In the last few years, when my client rankings go up or down I visit Algoroo to see if the bar is high that day. Rather than speculating about what happened at Google all I want to know is whether something did happened at Google, and that’s enough information for me. It solves the problem of “was it me, or was it Google?”. I control HTML, content and links (to some extent) while having zero control over what Google does. With no ability to understand what’s behind Google’s updates, all that’s left is speculation, and that’s not useful to me.
That said. Today I’ll make a small exception and highlight one, possibly useful observation.
January 2020 Core Update is significant in the sense that it triggered permanent SERP volatility that hasn’t been observed since the period between 2017 and 2018. This means that since the update, each day SERPs are more mixed up and diverse than the previous observed day.

This is potentially a good thing for smaller websites or those who previously didn’t get a chance to be visible for certain queries.
We’re still collecting data, so it’s yet to be seen how permanent this is (there’s a chance it could be a multi-day roll-out of the same strength), but this sort of trigger has happened multiple times throughout Google’s algo update history.

When I wrote about it back in 2014 I called them “SERP epochs”. We could be seeing a start of a new one.