We do not consolidate VIEs when we are not deemed to be the primary beneficiary. Our unconsolidated VIEs include securitization trusts and limited partnerships. The following table displays the carrying amount and classification of our assets and liabilities that relate to our involvement with unconsolidated securitization trusts.
September 30, 2018
December 31, 2017
(Dollars in millions)
Total trading securities
Total available-for-sale securities
Net carrying amount
Our maximum exposure to loss generally represents the greater of our recorded investment in the entity or the unpaid principal balance of the assets covered by our guaranty. However, our securities issued by Fannie Mae multi-class resecuritization trusts that are not consolidated do not give rise to any additional exposure to loss as we already consolidate the underlying collateral. The maximum exposure to loss related to unconsolidated mortgage-backed trusts was approximately $14 billion and $15 billion as of September 30, 2018 and December 31, 2017, respectively. The total assets of our unconsolidated securitization trusts were approximately $90 billion and $70 billion as of September 30, 2018 and December 31, 2017, respectively.
The maximum exposure to loss for our unconsolidated limited partnerships and similar legal entities, which consist of low-income housing tax credit investments, community investments and other entities, was $105 million and the related carrying value was $83 million as of September 30, 2018. As of December 31, 2017, the maximum exposure to loss was $105 million and the related carrying value was $82 million. The total assets of these limited partnership investments were $2.4 billion and $3.2 billion as of September 30, 2018 and December 31, 2017, respectively.
We issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the