Discounts For Lack Of Marketability - DLOM
  
There's no market for it. No buyers. No "comps." It's the house 90 miles from anything. It's the private internet company that has a lot of usage but no revenues or profits. It's the mutual fund that owns 15% of the shares outstanding of a company that trades only 1% of its total shares each week (if the fund ever wanted to get out or sell, there'd be steep price discounting, so even if the stock is trading at $15 a share, by the time the fund was finished selling, it'd be down to $5. The fund should carry those shares, likely not at $15, but at some discount due to their lack of marketability.)