It's not all over. I think what happened is relatively straight forward. I had two money sites go from #1 (same keyword, different cities) to lower first page, and top of second page respectively, in a significantly competitive and valuable niche. Both had the same link sources (my PBN), however, none of my other sites powered by those PBN nodes have been effected, nor have any of the PBN sites been deindexed. At this time, I'm confidently ruling out the prospect that "I've been hit", because the SERPs have changed significantly - it's not just my rankings that have changed, the entire SERPs appear to have changed significantly in each case. And, to further support the theory that this isn't an action against my sites, another site (different keyword entirely) using exactly the same page template as the 2 that slipped in rankings, and that has even less content, actually climbed from a long term position of #5 to #4, with exactly the same link source (my PBN nodes). My theory is this: There were a bunch of sites that were hit by the various iterations of Panda. Since being hit, those site owners have worked to improve their sites, with the goal of having the algorithmic penalty removed. Today, and indeed over the last few days, Panda has refreshed, and all those sites that were 'out of play' because they were under penalty, have had their penalties removed and are now back in play, which simply means that the set of sites competing for the top 100 rankings has changed (and significantly so, in many cases). Therefore, my sites (and your sites that slipped rankings), as relative to the top 100 competition, have by default changed in value, because the playing field changed over night. It's important to draw the distinction that I view this as a relative change in value, not a direct change in value - in the same way that in some cases the Euro might appear to weaken against the US dollar, when in fact it's the US dollar that strengthened, having the relative effect of causing the euro to appear to weaken. That is, a relative weakening. To continue the analogy, our sites that slipped in ranking are the Euros, and the sites that came out from penalty are the US dollars. There's nothing wrong with our Euros - the US dollars just strengthened. My recovery plan: 1) Add a bunch of PBN links, in the same way that I've been climbing rankings steadily on new domains for the last 12+ months. Assuming this causes *any* movement in the SERPs, I'll just continue adding those links, working on the theory that my slipped sites became less valuable overnight, as compared against the new top 100 competition, and I now need to work to increase it's value, by building more links. 2) Failing the above having a tangible result, I'll 301 my slipped money sites to new domains, and also point new high-value links at those domains. I'll also rebuild the sites on new domains, and compete against myself with both sites, and let the best man (site) win! I'm quite confident that my theory about a relative weakening caused by a changed playing field is accurate. I'm not under attack (nor is anyone who slipped rankings), I've not been hit, my PBN's haven't been taken out - it's simply that many of those domains that were suffering under penalty have now come out from that penalty, and have been re-entered into the game, fundamentally changing the state of play, literally overnight. I'll post updates here, either way.