I should also mention that the Fannie preferreds have a stated value which equals their LP value or redemption value. The exception is FNMFO which is $105K for redemption value (when called) vs $100K for liquidation preference (receivership).
Despite what some have posted, they DO NOT HAVE a "par" value. Whether through receivership or redemption, there is a specific listed value - either $25 or $50 depending on the series.