Repurchase and Reverse Repurchase Agreements

Repurchase Agreements

We pledge our securities as collateral under our borrowings structured as repurchase agreements with financial institutions. Interest rates on our borrowings are generally based on LIBOR plus or minus a margin and amounts available to be borrowed are dependent upon the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, type of security and liquidity conditions within the banking, mortgage finance and real estate industries. If the fair value of our pledged securities declines, lenders will typically require us to post additional collateral or pay down borrowings to re-establish agreed upon collateral requirements, referred to as "margin calls." Similarly, if the fair value of our pledged securities increases, lenders may release collateral back to us. As of December 31, 2018, we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 6.

As of December 31, 2018 and 2017, we had $75.7 billion and $50.3 billion, respectively, of repurchase agreements outstanding used to fund our investment portfolio. The terms and conditions of our repurchase agreements are typically negotiated on a transaction-by-transaction basis. Our repurchase agreements with original maturities greater than one year have floating interest rates based on an index plus or minus a fixed spread. The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of December 31, 2018 and 2017 (dollars in millions):



	December 31, 2018					December 31, 2017
Remaining Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity
≤ 1 month	$	48,533	2.88	%	9	$	19,771	1.59	%	11
> 1 to ≤ 3 months	20,991		2.57	%	56	16,150		1.50	%	50
> 3 to ≤ 6 months	2,218		2.65	%	167	7,287		1.50	%	130
> 6 to ≤ 9 months	200		3.19	%	208	2,361		1.66	%	225
> 9 to ≤ 12 months	950		2.80	%	279	202		1.64	%	297
> 12 to ≤ 24 months	2,200		2.91	%	438	1,700		1.84	%	468
> 24 to ≤ 36 months	625		3.11	%	776	2,200		1.80	%	803
> 36 to ≤ 48 months	—		—	%	—	625		1.90	%	1,141
Total	$	75,717	2.79	%	49	$	50,296	1.57	%	116

As of December 31, 2018 and 2017, $19.5 billion and $5.3 billion, respectively, of our repurchase agreements had a remaining maturity of one business day and none of our repurchase agreements were due on demand. As of December 31, 2018, we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 9 days and a weighted average interest rate of 2.90%. As of December 31, 2018 and 2017, 35% and 33%, respectively, of our repurchase agreement funding was sourced through our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC ("BES"). Amounts sourced through BES include funding from the General Collateral Finance Repo service ("GCF Repo") offered by the Fixed Income Clearing Corporation ("FICC"), which totaled 33% and 30% of our repurchase agreement funding outstanding as of December 31, 2018 and 2017, respectively.

Reverse Repurchase Agreements

As of December 31, 2018 and 2017, we had $21.8 billion and $11.0 billion, respectively, of reverse repurchase agreements outstanding used primarily to borrow securities to cover short sales of U.S. Treasury securities, for which we had associated obligations to return borrowed securities at fair value of $21.4 billion and $10.5 billion, respectively. As of December 31, 2018 and 2017, $4.5 billion and $2.7 billion, respectively, of our reverse repurchase agreements were with the FICC sourced through BES.