Mozcast did report the highest number out of the last 30 days - http://mozcast.com.
Fairly new sites should be seeing a boost here, as I'm seeing another round of deindexing of a lot of the older PBN (paid) links some of my niche sites have. This effect would drop older sites down who owned the PBN links, while it misses newer sites who's PBN links are newer and not on any Google hit list yet.
I'm gonna have to freshen up my link profile with some new PBN orders on my niche sites. But based on my research this should fix it.