Google SERP Volatility During December 2015 Explained

Dec 31, 2015
5 min read
Google Algorithm Update

Over the last couple of weeks, there seems to be a fair amount of volatility in the SERP Trackers that require a comment. It first started around the 16th of December and continued until the 31st of December. Despite the HTTPS update explaining some of the movement in the SERP Trackers, Google has also confirmed a continuation of the 19th November Update as a cause.

Before looking at the SERP trackers, it is useful to comment on a few things:

  • It is not Penguin - John Mueller, webmaster trends analyst at Google, confirmed in early December that the new Real-time Google Penguin Algorithm would not be rolled out until 2016.
  • Secondly, Google Panda was only recently (a few months ago) rolled out, and no chatter around the web indicates it is related to it. That being said, it is still possible that the update is Content Quality related, similar to the update of the 19th November 2015.
  • Thirdly, Google changed how it indexed websites that have both HTTP and HTTPS URLs available. By default, Google will now index the HTTPS URL. With HTTPS giving an SEO boost, this may explain some of the volatility shown in the SERP trackers.
  • Finally, on the 30th December 2015, Glenn Gabe stated that the latest volatility was “Tremors connected w/the 11/19 update have been continuous. I have seen more movement this week on websites impacted.”

Let’s take a look at the SERP Trackers

Looking at the SERP Trackers enable us to see how large \ significant any Google Updates are.

Rank Risk Index

The Rank Risk Index shows some significant volatility commencing on the 16th December 2015 and continuing through to the end of 2015. The first spike in volatility is partially explained by Google starting to rank HTTPS URLs as a priority to the normal HTTP ones. This may be the cause of the volatility, as Google recrawls the web over time.

Rank Ranger Risk Index.


MozCast gives quite a different picture to the Rank Risk Index. The only real spike is on the 12th December 2015, with the remainder of the month being reasonably calm. This doesn’t quite make sense, but one possibility could be due to how MozCast interprets the HTTPS changes. If so, it could indicate a lack of any Google Update, and more a simple change in the amount of HTTPS URL’s being indexed.



Algaroo occupies the middle ground between the Rank Risk Index and MozCast. Volatility starts on the 16th December 2015 with the HTTPS Update and continues until around the 24th December 2015. The SERP volatility is relatively quiet for the last week of 2015.

Algoroo SERP Volatility.

What have webmasters been saying around the web?

The main discussions have been ongoing at, with many webmasters reporting initial changes around the 14-16th December, and then again around the 29th - 30th December 2015.

~16th December Comments

My traffic logs and sales look just as sloppy as the search results. Poor sales, traffic coming from places that I never heard of in geography class, high bounce rates, low page views. All this the last weekend before Christmas? Unbelievable. - 17th December 2015

I see the same flux in UK SERPs today. Imo, it looks like panda, but as usual, who knows! - 18th December 2015

After 2 very good month of increasing traffic, conversions and user engagement, yesterday it went all down the drain. Very, very, very bad traffic, no sales thorugh Google traffic (from organics and GSA). High bounce, traffic from all over the world but not from Germany. We saw an increase of robots since yesterday. I think that it is a brand thing, Winners are big brands. I saw this dataset month ago. It seems pretty the same. Completely unrelated to the query while brands rule the

I think that it is a brand thing, Winners are big brands. I saw this dataset month ago. It seems pretty the same. Completely unrelated to the query while brands rule the SERPs. Very disappointing. Maybe a roll back to an prior panda version. - 18th December 2015

~30th December Comments

I am not sure what happened but yesterday I got a small uptick in traffic (about a 8-10%) and a big boost in conversions (about a 40% increase). I normally see a small uptick for both right after Christmas but nothing like what I saw yesterday. Did anyone else see this? - 29th December 2015

Our Google traffic has jumped sharply in the last few days, compared to the same days of the week earlier in December. Daily revenues are way up, too. - December 30th 2015

Without more widespread complaints, and with the HTTPS update and the usual reduction in traffic over the Christmas period it is tough to narrow down any possible cause based on these comments.

What did Google have to Say?

Fortunately, Glenn Gabe can clarify the situation a little more. The latest volatility is related to an older Google Update we reported on back in November:

The November update was Core Algorithm change, which many people at that time mentioned content quality as a possible impacting factor.

We, therefore, suspect that the SERP trackers were showing volatility due to two things, the continuation of the November update, and the changes to HTTPS indexing.