Fair Value Measurements

The Company uses various inputs in determining the fair value of its investments and measures these assets on a recurring basis. Assets and liabilities recorded at fair value in the consolidated balance sheets are categorized by the level of objectivity associated with the inputs used to measure their fair value. The following levels are directly related to the amount of subjectivity associated with the inputs to fair valuation of these assets and liabilities:


•	Level 1 - quoted prices in active markets for identical investments, which include U.S. treasury securities


•	Level 2 - other significant observable inputs (including quoted prices for similar investments, market corroborated inputs, etc.), which includes corporate debt securities


•	Level 3 - significant unobservable inputs

The inputs or methodology used for valuing securities are not necessarily an indication of the credit risk associated with investing in those securities. The following table provides the fair value measurements of applicable Company assets and liabilities that are measured at fair value on a recurring basis according to the fair value levels described above as of September 30, 2018 and December 31, 2017:



	Assets and Liabilities at Fair Value as of September 30, 2018
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	48,902	$	—	$	—	$	48,902
Short-term investments	125,588		12,807		—		138,395
Total cash and cash equivalents and investments	$	174,490	$	12,807	$	—	$	187,297



	Assets and Liabilities at Fair Value as of December 31, 2017
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	61,661	$	—	$	—	$	61,661
Short-term investments	222,148		26,979		—		249,127
Total cash and cash equivalents and investments	$	283,809	$	26,979	$	—	$	310,788

The Company did not have any Level 3 assets or liabilities as of September 30, 2018 or December 31, 2017. In March 2017, the Company satisfied its remaining contingent payment obligation to designees of Symphony Icon Holdings LLC. Prior to payment, the Symphony Icon purchase consideration liability, a Level 3 liability, was estimated using a probability-based income approach utilizing an appropriate discount rate. Changes in the fair value of the Symphony Icon purchase consideration liability were recorded as an increase or decrease in Symphony Icon purchase liability expense in the accompanying consolidated statements of comprehensive loss. The change in fair value of the purchase consideration liability was an increase of $2.1 million during the nine months ended September 30, 2017.

The Company also has assets that under certain conditions are subject to measurement at fair value on a non-recurring basis. These assets include goodwill associated with the acquisitions of Coelacanth Corporation in 2001 and Symphony Icon in 2010, and intangible assets associated with the acquisition of Symphony Icon in 2010. See Note 6, Arrangements with Symphony Icon, Inc., for additional information. For these assets, measurement at fair value in periods subsequent to their initial recognition is applicable if one or more is determined to be impaired.