贷款的guarantee fees将增加 an average 10 basis points

我刚收到下面这条讯息, 但不太明白它到底是什么意思. 这个g-fees是怎么算的啊? 为什么它会对贷款有影响? 影响会多大? 希望高手给于指教.

The Federal Housing Finance Agency (FHFA) has directed Fannie Mae and Freddie Mac to raise guarantee fees (g-fees) on single-family mortgages by an average of ten (10) basis points. The purpose of this increase is to encourage greater participation in the mortgage market by private firms, which is one of FHFA’s stated goals. This will negatively affect 30 years and 15 years fixed rate in the near future.