Fannie Mae-No Politics (FNMA)

[Wise Man]

You don't know the specifications of the security you purchased.
The underlying security in a Preferred Stock is an obligation.
The Treasury department also said so in the SPSPA:


The security "obligation" is a compromise of repayment, that is, a debenture that reflects the taxpayer's assistance, which must be paid back asap.

Subsection (c) any obligations of subsection (b) redeemable obligations, is the original UST backup of FnF in the Charter Act, at rates similar to Treasuries. It's included the SPS in this definition, also as a way to finance their operations as a last resort (either Equity or Debt) in the section Purposes, which is the one that specifies their (risky) Public Mission.