CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Securities classified as cash and cash equivalents and short-term investments as of March 31, 2019 and December 31, 2018 are summarized below (in thousands). Estimated fair value is based on quoted market prices for these investments.



March 31, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and cash equivalents
Cash	$	94,311	$	—	$	—		$	94,311
Money market funds	41		—		—			41
Commercial paper	14,594		—		(3		)	14,591
U.S. Treasury Securities	748		—		—			748
Total cash and cash equivalents	$	109,694	$	—	$	(3	)	$	109,691



December 31, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Cash and cash equivalents
Cash	$	95,660	$	—	$	—	$	95,660
Money market funds	11		—		—		11
Agency bond	1,250		—		—		1,250
Commercial paper	14,028		—		—		14,028
Total cash and cash equivalents	$	110,949	$	—	$	—	$	110,949

The Company considers all highly liquid investments with a maturity at date of purchase of three months or less to be cash equivalents. Cash and cash equivalents generally consist of cash on deposit with banks, money market instruments, U.S. Agency discount notes, commercial paper and corporate debt securities.

The Company invests its cash in money market funds and marketable securities including U.S. Treasury and government agency securities, commercial paper, and high-quality debt securities of financial and commercial institutions. To date, the Company has not experienced material losses on any of its balances. These securities are carried at fair value, which is based on readily available market information, with unrealized gains and losses included in “interest income and other (expense) income, net” in the consolidated statement of operations. The Company uses the specific identification method to determine the amount of realized gains or losses on sales of marketable securities. Realized gains or losses have been insignificant and are included in “interest income and other (expense) income, net” in the consolidated statement of operations.

As of March 31, 2019 and December 31, 2018, the Company did not hold any securities in a continuous loss position.