A basis point is one hundredth of a percentage point. A single basis point would look like this: 0.01%. Fifty basis points is a half a percentage point: 0.50%. 100 basis points equal one percentage point: 1.00%.
In finance, changes in the values of financial instruments or interest rates may be denoted in basis point. They are used to describe quantities less than one percent. When the Federal Reserve lowers its fed funds rate by a half a percent, the media may report that the fed funds rate was lowered by 50 basis points.
Similarly, the interest rate on a loan or debt instrument that is based on a reference rate, such as LIBOR or the Prime Rate, may have a spread quoted using the term basis point. The rate may be described as Prime Rate plus 50 basis point. If Prime Rate is 5%, then the rate on that loan or debt instrument would be 5.5%.