Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Summary of Fair Value Measurements of Company's Financial Assets and Liabilities

The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy (in thousands):


	March 31, 2019
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds	$	83,521	$	83,521	$	—	$	—
U.S. treasury notes		2,283		2,283		—		—
U.S. treasury securities		2,280		2,280		—		—
Corporate bonds		20,112		—		20,112		—
Commercial paper		32,060		—		32,060		—
Asset-backed securities		4,285		—		4,285		—
Total	$	144,541	$	88,084	$	56,457	$	—

Liabilities:
Derivative liability for exit fee	$	570	$	—	$	—	$	570
Total	$	570	$	—	$	—	$	570


	December 31, 2018
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds	$	73,238	$	73,238	$	—	$	—
U.S. treasury securities		3,996		3,996		—		—
Corporate bonds		34,590		—		34,590		—
Commercial paper		43,154		—		43,154		—
Asset-backed securities		9,378		—		9,378		—
Total	$	164,356	$	77,234	$	87,122	$	—

Liabilities:
Derivative liability for exit fee	$	533	$	—	$	—	$	533
Foreign currency derivative contracts		52	$	—	$	52	$	—
Total	$	585	$	—	$	52	$	533

Summary of Changes in the Fair Value of Recurring Measurements

Changes in the fair value of recurring measurements included in Level 3 of the fair value hierarchy are presented as other income (expense), net, in the Company's condensed consolidated statements of operations and were as follows for the three months ended March 31, 2019 (in thousands):


	Estimated Fair Value
	of Derivative Liability
Balance of Level 3 Liabilities at December 31, 2018	$	533
Change in estimated fair value of derivative liability for exit fee		37
Balance of Level 3 Liabilities at March 31, 2019	$	570