A Sleeper Hyip is used to show that the program has been running for a long time when, once the final plans and design are added, it's  officialy launched. Most sleepers pay lower interests and have no design at all. Just the default Goldcoders.

A Sleeper do not look attractive but this is intentional. The Sleeper Admin don't want many investors during this phase which typically last between 30 and 300 days. Be very careful joining a Sleeper. Many cheap admin can launch a program that looks like a sleeper but is really just intended to be a fast scam.