In fact, here is an updated SearchMetrics chart of the drop, it is a 78% loss in search visibility!
But now, the question is, was it Panda 4.0 that hit eBay or a manual action. Re/Code reports sources, that I have confirmed as well, that it was a manual action. Of course, Google won't comment but it is incredibly likely that eBay was hit with a manual action.
In fact, as refugeeks.com reported and the other tracking tools, the loss was specific to a single directory on eBay's site.
Doesn't Panda also impact parts of sites, like directories, not just whole sites. Yes, it is possible. So was this Panda or manual? Possibly both.
Does it matter if it was a manual action or algorithmic action? Yes! It changes how you go about fixing the issue and the timing of the recovery of the issue.