question about SEDO

I checked market activity of SEDO in buy domain option, there's a domain that is auction and 3 days left. But when I investigate the site, its already registered. My question is how did sedo make an auction for a domain that is already registered? or maybe sedo will make a proposal to the owner of that particular domain if the highest bidder win? the domain is in the "FEATURED AUCTION" area.

Sedo allows you to sell your domain without parking so may be you saw one of those.