It seems there has been a new Google ranking update targeting the link quality of the algorithm. Though the update remains unconfirmed. Many have called this update “Fred”.
There has been buzz that the update is more about spammy links. In the beginning of February another link related update renamed unconfirmed by Google. Another than this there was a content quality update on February 7th which again went unconfirmed.
Many automated ranking tools show changes, shifts and fluctuations in the rankings, indicating an update.