Since the Fred Update 8th March. There seems to be a somewhat weekly data refresh/tweak. Dates I catched so far. - 31.03.17 - 04.04.17 - 17/18.04.17 - 25.04.17 You can also monitor these on Semrush Sensor https://de.semrush.com/sensor?db=US&category=&date= Or by reading Barry Schwartz, who is nowadays annoucing a new Update each and every week. https://www.seroundtable.com/google-algorithm-update-23724.html Although is basically one and the same thing as one of my sites, gets hammered nearly weekly in the exact same pattern, to bounce back a day afterwards. So I'd say, it's dancing on the thin line of getting punished of the damn thing.