High-Yield Investment Programs (HYIP) are unregistered investments typically run by unlicensed individuals – and they are often frauds. The hallmark of an HYIP scam is the promise of incredible returns at little or no risk to the investor. A HYIP website might promise annual (or even monthly, weekly, or daily!) returns of 30 or 40 percent – or more. Some of these scams may use the term “prime bank” program. If you are approached online to invest in one of these, you should exercise extreme caution - they are likely frauds.
Source: http://investor.gov/glossary/glossary_terms/high-yield-investment-programs#.Us3C32RDuEg