CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Tables)

6 Months Ended

Jun. 30, 2019

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Schedule of cash, money market funds and short-term investments

Cash equivalents and short-term investments consist of the following (in thousands):

	June 30,		December 31,
	2019		2018
Cash equivalents - Money market funds	$	33,250	$	25,968
Cash equivalents - U.S government securities		9,979		—
Cash equivalents total	$	43,229	$	25,968

Cash equivalents in the tables above exclude cash demand deposits of $33.7 million and $56.2 million as of June 30, 2019 and December 31, 2018, respectively.

	June 30,		December 31,
Short-term Investments	2019		2018
U.S. treasury securities	$	187,695	$	265,393
U.S. government agency securities		139,546		120,978
Short-term investments total	$	327,241	$	386,371

Schedule of cost and fair value of cash equivalents and short-term investments

The cost and fair value of cash equivalents and short-term investments at June 30, 2019 and December 31, 2018 were as follows (in thousands):

					Gross		Gross
					Unrealized		Unrealized
As of June 30, 2019	Cost		Accretion		Gains		Losses		Fair Value
U.S. treasury securities	$	186,540	$	923	$	232	$	—	$	187,695
U.S. government agency securities		138,499		907		140		—		139,546
Total	$	325,039	$	1,830	$	372	$	—	$	327,241

					Gross		Gross
					Unrealized		Unrealized
As of December 31, 2018	Cost		Accretion		Gains		Losses		Fair Value
U.S. treasury securities	$	264,619	$	813	$	19	$	(58)	$	265,393
U.S. government agency securities		120,653		328		21		(24)		120,978
Total	$	385,272	$	1,141	$	40	$	(82)	$	386,371