Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

6. Fair Value of Financial Instruments

Fair value is an exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value is determined based on observable and unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, while unobservable inputs reflect certain market assumptions. As a basis for considering such assumptions, GAAP establishes a three-tier value hierarchy, which prioritizes the inputs used to develop the assumptions and for measuring fair value as follows: (Level 1) observable inputs such as quoted prices in active markets for identical assets; (Level 2) inputs other than the quoted prices in active markets that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value.

Recurring Fair Value Measurements

The Company’s cash, restricted cash, accounts receivable, prepaid expenses, and other current assets, accounts payable, accrued expenses and variable interest rate note payable are recorded at cost, which approximates fair value due to their short-term nature.

The following tables summarize assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2017 and the input categories associated with those assets and liabilities:

	December 31, 2018
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	16,292	$	—	$	—
Commercial paper				1,998
Totals	$	16,292	$	1,998	$	—
Marketable securities
Commercial paper	$	—	$	31,766	$	—
Corporate debt securities		—		7,479		—
Government securities		—		11,954		—
Totals	$	—	$	51,199	$	—

	December 31, 2017
(in thousands)	Level 1		Level 2		Level 3
Assets:
Money market funds	$	89,310	$	—	$	—
Totals	$	89,310	$	—	$	—

There were no changes in valuation techniques or transfers between the fair value measurement levels during the years ended December 31, 2018 or 2017. There were no liabilities measured at fair value on a recurring basis as of December 31, 2018.