Preforeclosure and Auction Properties...???

[Katharine Gonzalez]

Driving around I came across a few properties with online auction signs not active on the MLS. The properties are listed as bank-owned on the tax assessor's site and some of the auction dates have past. I'm wondering why the banks choose to auction some properties and simply list others? Are any properties not bought at auction? How might I go about finding out if a property sold at auction?