2015 has been unkind to the mortgage REIT sector. The iShares Mortgage Real Estate Capped (REM), a basket of the largest and most actively traded mortgage REITs, is down a little over 8% year to date. Including the large dividend, that loss shrinks to about 4%. But it's been a rough ride, and I haven't seen any indication that it's over. This is every value investor's frustration: A cheap sector that just keeps getting cheaper.