Fair Value Measurements

Fair value of financial instruments

The carrying amounts of financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, accounts payable, deposits and accrued expenses, approximate fair value due to the short maturity of these instruments. Accordingly, these instruments are not presented in the table below. The following table provides the estimated fair values of the remaining financial instruments:



	As of June 30, 2017				As of December 31, 2016
(in thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
Financial Instruments:
Cost method investment ⁽¹⁾	$	1,016	$	1,016	$	1,016	$	1,016
Highview technology license payable	$	210	$	210	$	207	$	207

(1) Fair value is based on the investee's recently completed equity raise at £2.00 per share. Refer to Note 3 for further discussion of this investment. The fair value measurement represents a Level 3 measurement as it is based on significant inputs not observable in the market.

Concentration of credit risk

The Company's financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents and restricted cash, which were held at one and two financial institutions as of June 30, 2017 and December 31, 2016, respectively. If those institutions were to be unable to perform their obligations, the Company would be at risk regarding the amount of cash and investments in excess of the Federal Deposit Insurance Corporation limits ($250 thousand) that would be returned to the Company.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

As of June 30, 2017 and December 31, 2016, the Company had no financial instruments carried and measured at fair value on a recurring basis.