The difference between the general collateral rate (general repo rate) and the specific collateral rate (special repo rate):

s = r- R

Where: s is the repo rate spread; r is the general repo rate (GC: general collateral rate); R is the special repo rate (SC: special collateral rate) (r ≥ R or s ≥ 0).

The GC-SC repo rate spread is positive when the general repo rate is larger than the special repo rate and the collateral is said to be on special. The GC-SC repo rate spread allows the holder of the collateral to earn a repo dividend (it equals the GC-SC repo rate spread times the value of security such as a bond).

It is also known as a repo spread or a repo rate spread.