So the update we broke yesterday, that Google update that I said didn't feel like Panda, is not Panda as I said. But Google did say that it was a normal "improvements to our search algorithms and the web is constantly evolving," a Google spokesperson told me.
Gary Illyes on Twitter added, "can't comment more on this though, we make hundreds of changes every year, you know the rest."
John Mueller said in a video hangout yesterday, what Google confirmed to me the other day as well. Google's spokesperson said, "this is not a Panda update," and John Mueller said in the video it was not Panda. Here are the two places John commented on it not being Panda or Penguin:
18:05 minutes in where he also said not Penguin:
Then Dr. Pete thought it was HTTPS getting a boost, but Gary from Google said no to that on Twitter. But I suspect Mozcast and the other tools saw a major spike because the number one ranked site in Google, Wikipedia did go HTTPS recently and the tools picked it up as a new domain ranking?
So while Google did do an update, I doubt it was as significant as the tools say. At least, my radar by watching the forums and the SEO community, the chatter is simply not that high around individuals complaining about ranking changes.
This seems more like the May 1st Google update that they denied and then confirmed later as a core ranking change.
So this was a core ranking change, which did not impact as many people as the automated tools suggested in my opinion.
Forum discussion at Twitter, WebmasterWorld and Black Hat Forums.