You need to change brokers....
Interactive Brokers had greater than 10,000,000 shares available today....
Symbol: FNM
Availability: >10'000'000
Exchanges: ARCA, ATD, BATS, CBSX, CHX, CSFBALGO, CSFBCROSS, DARK1, DBALGO, DRCTEDGE, EDGEA, IDEAL, ISE, ISLAND, JEFFALGO, LAVA, NASDAQQ, NITEECN, NSX, NYSE, TMBR, TRACKECN, VWAP, MIBSX, IBSX