Note 3 - Cash, Cash Equivalents, Investments and Restricted Cash

12 Months Ended

Dec. 31, 2023

Notes to Financial Statements

Financial Instruments Disclosure [Text Block]

3.  CASH, CASH EQUIVALENTS, INVESTMENTS AND RESTRICTED CASH

The following is a summary of the Company’s cash, cash equivalents and debt investments (in thousands): 

	December 31,
	2023		2022
Cash	$	392,329	$	273,145
Money market funds		135,514		15,462
Certificates of deposit		127,123		130,467
Corporate debt securities		95,101		292,586
Commercial paper		-		17,928
U.S. treasuries and government agency bonds		358,409		8,285
Auction-rate securities backed by student-loan notes		567		1,711
Total	$	1,109,043	$	739,584

	December 31,
	2023		2022
Reported as:
Cash and cash equivalents	$	527,843	$	288,607
Short-term investments		580,633		449,266
Investment within other long-term assets		567		1,711
Total	$	1,109,043	$	739,584

The following table summarizes the contractual maturities of the short-term and long-term available-for-sale investments as of December 31, 2023 (in thousands): 

	Amortized Cost		Fair Value
Due in less than 1 year	$	398,670	$	397,884
Due in 1 - 5 years		183,266		182,749
Due in greater than 5 years		574		567
Total	$	582,510	$	581,200

Gross realized gains and losses were not material for the periods presented.

The following tables summarize the unrealized gain and loss positions related to the available-for sale investments (in thousands): 

	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market funds	$	135,514	$	-	$	-		$	135,514
Certificates of deposit		127,123		-		-			127,123
Corporate debt securities		96,636		4		(1,539	)		95,101
U.S. treasuries and government agency bonds		358,177		327		(95	)		358,409
Auction-rate securities backed by student-loan notes		574		-		(7	)		567
Total	$	718,024	$	331	$	(1,641	)	$	716,714

	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Money market funds	$	15,462	$	-	$	-		$	15,462
Certificates of deposit		130,467		-		-			130,467
Corporate debt securities		300,529		18		(7,961	)		292,586
Commercial paper		17,928		-		-			17,928
U.S. treasuries and government agency bonds		8,487		-		(202	)		8,285
Auction-rate securities backed by student-loan notes		1,770		-		(59	)		1,711
Total	$	474,643	$	18	$	(8,222	)	$	466,439

The following tables present information about the available-for-sale investments that had been in a continuous unrealized loss position for less than 12 months and for greater than 12 months (in thousands):

	December 31, 2023
	Less than 12 Months					Greater than 12 Months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate debt securities	$	20,792	$	(19	)	$	70,806	$	(1,520	)	$	91,598	$	(1,539	)
U.S. treasuries and government agency bonds		97,599		(95	)		-		-			97,599		(95	)
Auction-rate securities backed by student-loan notes		-		-			567		(7	)		567		(7	)
Total	$	118,391	$	(114	)	$	71,373	$	(1,527	)	$	189,764	$	(1,641	)

	December 31, 2022
	Less than 12 Months					Greater than 12 Months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate debt securities	$	72,943	$	(973	)	$	202,074	$	(6,988	)	$	275,017	$	(7,961	)
U.S. treasuries and government agency bonds		987		(2	)		7,298		(200	)		8,285		(202	)
Auction-rate securities backed by student-loan notes		-		-			1,711		(59	)		1,711		(59	)
Total	$	73,930	$	(975	)	$	211,083	$	(7,247	)	$	285,013	$	(8,222	)

An impairment exists when the fair value of an investment is less than its amortized cost basis. As of December 31, 2023 and 2022, the Company did not consider the impairment of its investments to be a result of credit losses. The Company typically invests in highly rated securities, with the primary objective of minimizing the potential risk of principal loss. The Company’s investment policy generally requires securities to be investment grade and limits the amount of credit exposure to any one issuer. When evaluating a debt security for impairment, management reviews factors such as the Company’s intent to sell, or whether it will more likely than not be required to sell, the security before recovery of its amortized cost basis, the extent to which the fair value of the security is less than its cost, the financial condition of the issuer and the credit quality of the investment.

Non-Marketable Equity Investment

In November 2020, the Company made an equity investment in a privately held Swiss company (the “Investee”) that is accounted for under the measurement alternative. In April 2022, the Company made an additional investment in the form of a convertible loan. One member of the Board of Directors was an executive officer of a company that has a commercial relationship with the Investee. In addition, the Company’s Chief Executive Officer had a personal investment in the Investee and was on the Investee’s Board of Directors. As of December 31, 2022, the Company’s investment in the Investee, which is denominated in Swiss Franc, had a carrying value of $5.4 million.

In May 2023, the Company sold all its investments in the Investee for $7.4 million and recorded a gain of $1.4 million, which was included as a component of other income (expense), net, in the Consolidated Statements of Operations for the year ended December 31, 2023.

Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported on the Consolidated Balance Sheets to the amounts reported on the Consolidated Statements of Cash Flows (in thousands):   

	December 31,
	2023		2022
Cash and cash equivalents	$	527,843	$	288,607
Restricted cash included in other current assets		33,204		-
Restricted cash included in other long-term assets		134		122
Total cash, cash equivalents and restricted cash reported on the Consolidated Statements of Cash Flows	$	561,181	$	288,729

As of December 31, 2023, restricted cash included in other current assets was related to preliminary purchase consideration held in a trust account in connection with the Company’s recent acquisition. See Note 17 for additional information. As of December 31, 2023 and 2022, restricted cash included in other long-term assets was related to a security deposit that is set aside in a bank account and cannot be withdrawn by the Company under the terms of a lease agreement. The restriction will end upon the expiration of the lease.