On June 17, Google's algorithm seemed to get a mysterious jolt with a mysterious update that Google deemed a routine, non-major change. Google specifically said the update was not related to Panda, Penguin, or HTTPS. They wouldn't comment further.
They just said, "We’re always making improvements to our search algorithms and the web is constantly evolving. We’re going to continue to work on improvements across the board."
According to MozCast, which measures the “temperature” of patterns of the Google algorithm, the update came in at 101.8°F. For comparison, the first Penguin update only registered at 93.1°.
Since initial reports on the update, Searchmetrics has analyzed it a bit, and found that news sites are benefiting most, and that it appears to be related to trending keywords and real time hot topics. Top winners, according to the company, were WSJ.com, USAToday.com, Dailymail.co.uk, BusinessInsider.com, Time.com, NBCNews.com, LATimes.com, NYPost.com, TechCrunch.com,FoxNews.com, Steampowered.com, BizJournals.com, TheVerge.com, Fortune.com, Gizmodo.com, Dict.cc, HollywoodLife.com, TechTarget.com, and WindowsPhone.com.
Most of these sites publish "fresh and newsworthy" content on a regular basis, as Searchmetrics notes.
The update coincides with a major refresh of Google Trends, which now provides data in real time, and takes into account trends on YouTube and Google News. Google hasn't confirmed the connection here, but it seems like the most likely explanation at this point.
As Searchmetrics notes, Google also has the Twitter fire hose now, so that's more real time data it can use. It's unclear whether or not that's connected. The only use of this data that has actually been announced comes in the form of tweets appearing in Google's mobile results, but it's probably safe to say that Google can tap into this for other reasons, that have bigger implications than that specific feature.
When the update was spotted by Moz, they dubbed it the Colossus update. Searchmetrics is calling it the seemingly more fitting "News-wave" update. I don't know if either name will stick, but it does appear that freshness is once again a major priority of the Google algorithm. This has been taken too far by Google in the past, in my opinion, so we'll see how it goes this time.
Interestingly, Searchmetrics reports that Wikipedia has seen a bit of drop in SEO visibility as a result of the update. There was some speculation initially that the shakeup in tools like Mozcast was related to Wikipedia switching to HTTPS. Since Wikipedia is usually the top result for many pages, it any changes with the site could significantly change SERPs in general. According to Searchmetrics, however, Wikipedia's placement has dropped a little due to news sites ranking for some terms.