After a long wait, we finally saw the May Core Update. When the update started, the Rank Risk Index reported violent SERP fluctuations starting on May 26th. Fluctuation levels quickly returned to normal the following day and remained that way until Google announced that the update was over.
The story was far from over.
We then saw violent SERP fluctuations starting again on June 20th. What’s more, the fluctuations continued all the way to June 29th.
We can only speculate that the updates are related.