FAIR VALUE MEASUREMENTS

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

2. FAIR VALUE MEASUREMENTS

Cash Equivalents and Marketable Securities

Cash equivalents, restricted cash and marketable securities by security type at September 30, 2022 were as follows:

			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	17,362	$	—	$	—		$	17,362
Commercial paper		34,159		—		(7	)		34,152
	$	51,521	$	—	$	(7	)	$	51,514
Restricted cash:
Money market fund	$	93	$	—	$	—		$	93
Certificate of deposit		271		—		—			271
	$	364	$	—	$	—		$	364
Marketable securities:
U.S. Treasury securities (due in less    than one year)	$	24,493	$	—	$	(174	)	$	24,319
Municipal securities (due in less than    one year)		3,000		—		(50	)		2,950
Government-sponsored enterprise    securities (due in less than one year)		13,325		3		(29	)		13,299
Commercial paper (due in less than    one year)		67,432		—		(215	)		67,217
Corporate notes (due in less than    one year)		26,068		—		(169	)		25,899
	$	134,318	$	3	$	(637	)	$	133,684

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2021 were as follows:

			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	24,207	$	—	$	—		$	24,207
Commercial paper		7,499		—		—			7,499
	$	31,706	$	—	$	—		$	31,706
Restricted cash:
Money market fund	$	93	$	—	$	—		$	93
Certificate of deposit		271		—		—			271
	$	364	$	—	$	—		$	364
Marketable securities:
U.S. Treasury securities (due in less than    one year)	$	15,585	$	—	$	(18	)	$	15,567
U.S. Treasury securities (due in one to    two years)		1,524		—		(3	)		1,521
Municipal securities (due in one to    two years)		3,000		—		(15	)		2,985
Government-sponsored enterprise    securities (due in less than one year)		12,500		—		(7	)		12,493
Commercial paper (due in less than    one year)		84,398		2		(38	)		84,362
Corporate notes (due in less than one year)		36,444		2		(17	)		36,429
Corporate notes (due in one to two years)		24,224		—		(79	)		24,145
	$	177,675	$	4	$	(177	)	$	177,502

Cash equivalents and marketable securities with unrealized losses that have been in a continuous unrealized loss position for less than 12 months and 12 months or longer at September 30, 2022 and December 31, 2021 were as follows:

	Less Than 12 Months					12 Months or Longer					Total
			Gross					Gross					Gross
	Estimated		Unrealized			Estimated		Unrealized			Estimated		Unrealized
(In thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
As of September 30, 2022:
U.S. Treasury securities (due in    less than one year)	$	17,333	$	(147	)	$	6,986	$	(27	)	$	24,319	$	(174	)
Municipal securities (due in less    than one year)		2,950		(50	)		—		—			2,950		(50	)
Government-sponsored enterprise    securities (due in less than    one year)		2,956		—			4,971		(29	)		7,927		(29	)
Commercial paper (due in less    than one year)		99,936		(222	)		—		—			99,936		(222	)
Corporate notes (due in less than    one year)		5,991		(15	)		19,908		(154	)		25,899		(169	)
	$	129,166	$	(434	)	$	31,865	$	(210	)	$	161,031	$	(644	)
As of December 31, 2021:
U.S. Treasury securities (due in    less than one year)	$	15,567	$	(18	)	$	—	$	—		$	15,567	$	(18	)
U.S. Treasury securities (due in    one to two years)		1,521		(3	)		—		—			1,521		(3	)
Municipal securities (due in one    to two years)		2,985		(15	)		—		—			2,985		(15	)
Government-sponsored enterprise    securities (due in less than    one year)		1,500		—			4,993		(7	)		6,493		(7	)
Commercial paper (due in less    than one year)		66,872		(38	)		—		—			66,872		(38	)
Corporate notes (due in less than    one year)		16,001		(17	)		—		—			16,001		(17	)
Corporate notes (due in one to    two years)		24,145		(79	)		—		—			24,145		(79	)
	$	128,591	$	(170	)	$	4,993	$	(7	)	$	133,584	$	(177	)

The gross unrealized losses related to U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper and corporate notes as of September 30, 2022 and December 31, 2021 were due to changes in interest rates and not credit risk. We determined that the gross unrealized losses on our cash equivalents and marketable securities as of September 30, 2022 and December 31, 2021 were temporary in nature. Our exposure to unrealized losses may increase in the future due to the economic pressures or uncertainties associated with local or global economic recessions as a result of the ongoing COVID-19 pandemic and ongoing geopolitical events, such as the current military conflict between Ukraine and Russia. We review our investments quarterly to identify and evaluate whether any investments have indications of possible other-than-temporary impairment. Factors considered in determining whether a loss is temporary include the length of time and extent to which the fair value has been less than the amortized cost basis and whether we intend to sell the security or whether it is more likely than not that we would be required to sell the security before recovery of the amortized cost basis. We currently do not intend to sell these securities before recovery of their amortized cost bases.

Fair Value on a Recurring Basis

We categorize financial instruments recorded at fair value on our condensed consolidated balance sheets based upon the level of judgment associated with inputs used to measure their fair value. The categories are as follows:

Level 1	—	Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis.
Level 2	—	Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.
Level 3	—	Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Money market funds are categorized as Level 1 within the fair value hierarchy as their fair values are based on quoted prices available in active markets. U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper, and corporate notes are categorized as Level 2 within the fair value hierarchy as their fair values are estimated by using pricing models, quoted prices of securities with similar characteristics or discounted cash flows.

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of September 30, 2022 and December 31, 2021 and indicates the fair value category assigned.

	Fair Value Measurements at Reporting Date Using
	Quoted Prices in				Significant
	Active Markets for		Significant Other		Unobservable
	Identical Assets		Observable Inputs		Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
As of September 30, 2022:
Money market funds(1)	$	17,362	$	—	$	—	$	17,362
U.S. Treasury securities(2)		—		24,319		—		24,319
Municipal securities(2)		—		2,950		—		2,950
Government-sponsored enterprise    securities(2)		—		13,299		—		13,299
Commercial paper(1)(2)		—		101,369		—		101,369
Corporate notes(2)		—		25,899		—		25,899
Total	$	17,362	$	167,836	$	—	$	185,198
As of December 31, 2021:
Money market funds(1)	$	24,207	$	—	$	—	$	24,207
U.S. Treasury securities(2)(3)		—		17,088		—		17,088
Municipal securities(3)		—		2,985		—		2,985
Government-sponsored enterprise    securities(2)		—		12,493		—		12,493
Commercial paper(1)(2)		—		91,861		—		91,861
Corporate notes(2)(3)		—		60,574		—		60,574
Total	$	24,207	$	185,001	$	—	$	209,208

(1)Included in cash and cash equivalents on our condensed consolidated balance sheets.

(2)Included in current portion of marketable securities on our condensed consolidated balance sheets.

(3)Included in noncurrent portion of marketable securities on our condensed consolidated balance sheets.