Fannie Mae's gross mortgage portfolio plummeted to a compound annualized rate of 27.2% in February, according to the government-sponsored enterprise's monthly summary.

The GSE's gross mortgage portfolio continues to decline, dropping a bit each month.

The book of mortgage business continued to decrease at a compound annualized rate of 1.7% last month, down from 1.8% in January. 

In addition, the conventional single-family, serious delinquency rate declined five basis points to 3.13% in February. 

The multifamily serious delinquency rate went the opposite direction, rising six basis points to 0.41% in the latest report.

Fannie Mae completed 14,205 loan modifications in February, for a total of 29,128 loan mods in the first two months of the year.