Have you bought yet?
If you are talking about bank owned properties, yes, they do go very fast. Investors are very smart, they check through a Fannie Mae website and often times know about the properties even before they go on the market. They also pay cash. Banks/lenders like cash because they can close and seal the deals in two weeks. Often times, the listing agents will price it so low to lure more buyers to the properties, thus creating a frenzy and multiple offers. But always know that the banks/ lenders will take a low cash offer over a good conventional loan.