Central banks don't account for assets or liabilities at fair value.
They only have one shareholder and no stock price, and they aren't meant to make a profit. (Their role is to create economic conditions where everyone can make a profit.) If they ever run out of capital (as the RBA did last year) the government just gives them some more.
I am off to the Pais de Basque for Christmas in the morning. Stay safe everyone!
Happy Christmas
Feliz Navidad
Bon Nadal
Eguberri*
(.... don't ask me for the Mallorcean.)