Phantom Update is a term coined by the SEO industry for significant fluctuations in search rankings caused by a Google update that was not officially announced, nor was there any warning given for said update. There have been two major phantom updates, one in May of 2013 and one in May 2015.
Phantom Update #1, May 2013
Numerous websites reported ranking fluctuations starting on 8th May 2013, a couple of weeks before the official roll out of Penguin 2.0. There was no official explanation was given for these fluctuations and experts were unsure as to whether this was a beta style test for Penguin 2.0 or a hybrid of Panda and Penguin. This ambiguity as exactly what this update targeted led to Glenn Gabe naming the apparent update ‘phantom’.
Phantom Update #2, May 2015
Now known as The Quality Update, much like the first phantom update there was significant confusion as to the cause of the associated ranking fluctuations due to its proximity to the much anticipated #mobilegeddon or ‘mobile-friendly’ update.
Both phantom updates have appeared to be far reaching updates, with some well known and high traffic sites suffering losses in traffic of nearly a quarter. Google tends to keep their cards pretty close to their chest when it comes to any update which is understandable considering the manipulative behaviour that has occurred when people attempt to abuse their supposed knowledge of how their algorithm works. Regardless though, Google tend to release tit bits of information in regards to updates whether that be a pre warning (such as in the case of #mobilegeddon) or an announcement of the update’s roll out. With these Phantom updates there was none of this associated information, hence the name, although in the second instance Google did confirm suspicions that it was an update focussed on content quality. In fact, it appears that both updates looked at reducing visibility for low quality content.