Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2019

Marketable securities as of September 30, 2019 and December 31, 2018 consisted of the following:



September 30, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market mutual funds	$	46,325	$	—	$	—	$	46,325
Total marketable securities designated as available-for-sale	$	46,325	$	—	$	—	$	46,325



December 31, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market mutual funds	$	25	$	—	$	—	$	25
Total marketable securities designated as available-for-sale	$	25	$	—	$	—	$	25

Amortized Costs and Fair Value of Marketable Securities

The amortized costs and fair value of marketable securities as of September 30, 2019 and December 31, 2018 are shown below by effective maturity. Effective maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.



September 30, 2019	Amortized Cost		Fair Value
Due in less than one year	$	—	$	—
December 31, 2018	Amortized Cost		Fair Value
Due in less than one year	$	—	$	—