You are expected one of them to close? Without having its registry taken over? Highly unlikely. I expect that if one did suddenly fail and have to close, the assets would be quickly reassigned.
Well, a Google search on 'domain registrar out of business' gets a few results. The most recent I saw was 2011. And a big failure in 2007. »en.m.wikipedia.org/wiki/ ··· isterFly
