Any important change in SERPs between Nov 17th and Nov 20th?

[emerlo]

I've noticed important changes in visibility for some websites, between Nov 17th and Nov 20th. Also some of the webs that monitor SERPs have detected similar stuff (Including Mozcast). Do you know if an important change in SERPs took place during those days?

[Mobilio]

Yes, there was unannounced update:http://www.hmtweb.com/marketing-blog/unconfirmed-google-algorithm-updates-2015/

[emerlo]

Thank you Peter!