INVESTMENTS

All of our investment securities that have a contractual maturity date greater than three months are classified as available-for-sale (AFS). The amortized cost, gross unrealized gains, gross unrealized losses, and fair values of our investments as of June 30, 2018 and December 31, 2017 are presented below:



	June 30, 2018
(in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Asset-backed securities	$	38	$	—	$	—	$	38
Corporate bonds	87		—		—		87
U.S. government agencies and government- sponsored agencies	6		—		—		6
U.S. treasuries	34		—		—		34
Exchange traded fund	1		—		—		1
Other debt securities	11		—		—		11
Total	$	177	$	—	$	—	$	177



	December 31, 2017
(in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasuries	$	37	$	—	$	—	$	37
Exchange traded fund	1		—		—		1
Total	$	38	$	—	$	—	$	38

Investments in a continuous unrealized loss position for less than 12 months and 12 months or more as of June 30, 2018 and December 31, 2017 are presented below.



	June 30, 2018
	Less than 12 months				12 months or more				Total
(in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Asset-backed securities	$	26	$	—	$	—	$	—	$	26	$	—
Corporate bonds	82		—		—		—		82		—
U.S. government agencies and government-sponsored agencies	5		—		—		—		5		—
U.S. treasuries	20		—		10		—		30		—
Other debt securities	2		—		—		—		2		—
Total	$	135	$	—	$	10	$	—	$	145	$	—



	December 31, 2017
	Less than 12 months				12 months or more				Total
(in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. treasuries	$	5	$	—	$	24	$	—	$	29	$	—
Total	$	5	$	—	$	24	$	—	$	29	$	—

Unrealized losses on fixed income securities are principally caused by changes in interest rates and the financial condition of the issuer. In analyzing an issuer's financial condition, we consider whether the securities are issued by the federal government or its agencies, whether downgrades by credit rating agencies have occurred, and industry analysts' reports. As we have the ability to hold these investments until maturity, or for the foreseeable future, no decline was deemed to be other-than-temporary.

The fair value of debt investments by contractual maturity (actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties) are shown below.



	June 30, 2018
(in millions)	One year or less		Over One Year Through Five Years		Over Five Years Through Ten Years		Over Ten Years		Fair Value
Asset-backed securities	$	2	$	32	$	3	$	1	$	38
Corporate bonds	24		63		—		—		87
U.S. government agencies and government-sponsored agencies	2		—		—		4		6
U.S. treasuries	2		32		—		—		34
Other debt securities	—		—		—		11		11
Total	$	30	$	127	$	3	$	16	$	176



	December 31, 2017
(in millions)	One year or less		Over One Year Through Five Years		Over Five Years Through Ten Years		Over Ten Years		Fair Value
U.S. treasuries	$	—	$	37	$	—	$	—	$	37
Total	$	—	$	37	$	—	$	—	$	37

There were immaterial gross realized gains and losses from sales of investments for the three and six months periods ended June 30, 2018 and 2017.

The fair value of our investments in an unrealized loss position represented 83% and 78% of the total fair value of all investments as of June 30, 2018 and December 31, 2017, respectively.

Our asset-backed securities include auto loan/lease, credit card, and equipment leases with investment-grade ratings.

Our corporate bonds include investment-grade debt securities from a wide variety of issuers, industries, and sectors.

Our U.S. government agencies and government-sponsored agencies securities primarily include commercial mortgage-backed securities and mortgage backed securities consisting of Federal Home Loan Mortgage Corporation and Federal National Mortgage Association securities with investment-grade ratings.

Our other debt securities primarily include mortgage-backed securities with investment-grade ratings issued by institutions without federal backing.