Cash and Cash Equivalents, and Investments and Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Cash and Cash Equivalents [Abstract]

Cash and Cash Equivalents, and Investments and Fair Value Measurements

The following tables present our cash and cash equivalents, and investments’ fair value level classification, adjusted cost, unrealized gain, unrealized loss and fair value as of December 31, 2023 and 2022 (in thousands):


	December 31, 2023
	Fair Value Level	Adjusted Cost		Unrealized Gain		Unrealized Loss		Fair Value
Cash and cash equivalents:
Cash		$	45,050	$	—	$	—	$	45,050
Money market funds	Level 1	90,707		—		—		90,707
Total cash and cash equivalents		$	135,757	$	—	$	—	$	135,757
Short-term investments:

Corporate debt securities	Level 2	$	69,548	$	—	$	(170)	$	69,378
U.S. treasury securities	Level 1	25,734		—		(114)		25,620
Agency bonds	Level 2	99,505		—		(246)		99,259
Total short-term investments		$	194,787	$	—	$	(530)	$	194,257
Long-term investments:
Corporate debt securities	Level 2	$	191,467	$	898	$	(213)	$	192,152

U.S. treasury securities	Level 1	57,287		165		(57)		57,395
Total long-term investments		$	248,754	$	1,063	$	(270)	$	249,547


	December 31, 2022
	Fair Value Level	Adjusted Cost		Unrealized Gain		Unrealized Loss		Fair Value
Cash and cash equivalents:
Cash		$	33,532	$	—	$	—	$	33,532
Money market funds	Level 1	440,145		—		—		440,145



Total cash and cash equivalents		$	473,677	$	—	$	—	$	473,677
Short-term investments:
Commercial paper	Level 2	$	11,744	$	—	$	(29)	$	11,715
Corporate debt securities	Level 2	491,459		—		(4,130)		487,329
U.S. treasury securities	Level 1	85,271		—		(342)		84,929

Total short-term investments		$	588,474	$	—	$	(4,501)	$	583,973
Long-term investments:
Corporate debt securities	Level 2	$	125,735	$	158	$	(909)	$	124,984
U.S. treasury securities	Level 1	$	30,633	$	122	$	—	$	30,755
Agency bonds	Level 2	60,635		—		(141)		60,494
Total long-term investments		$	217,003	$	280	$	(1,050)	$	216,233

As of December 31, 2023, we determined that the declines in the market value of our investment portfolio were not driven by credit related factors. During the years ended December 31, 2023, 2022 and 2021, we did not recognize any losses on our investments due to credit related factors.

The following table presents the gross realized gain and loss related to our investments (in thousands):


	Years Ended December 31,
		2023		2022		2021
Realized gain		$	346	$	64	$	84
Realized loss		(2,452)		(9,739)		(262)
Realized (loss)/gain on sale of investments		$	(2,106)	$	(9,675)	$	(178)

The following table presents our cash equivalents and investments' adjusted cost and fair value by contractual maturity as of December 31, 2023 (in thousands):


	December 31, 2023
	Cost		Fair Value
Due within one year	$	194,787	$	194,257
Due after one year through three years	248,754		249,547
Investments not due at a single maturity date	90,707		90,707
Total	$	534,248	$	534,511

Investments not due at a single maturity date in the preceding table consisted of money market funds.

Strategic Investments

In May 2023, we entered into a $15.0 million commitment to invest in Sound Ventures AI Fund, L.P. (Sound Ventures), a limited partnership that invests in AI companies, for an approximate 6% ownership. We accounted for our investment under the equity method of accounting. During the year ended December 31, 2023, we funded $11.8 million of our investment commitment. As of December 31, 2023, we had an unfunded investment commitment of $3.2 million. On January 1, 2024, we sold our partnership interest in Sound Ventures, along with all rights, duties and obligations, including the obligation to fund the remaining balance of our capital commitment, for $15.5 million. The initial accounting for the sale is in process as of the issuance date of our financial statements and therefore we are unable to make any additional disclosures.

In July 2022, we completed an investment of $6.0 million in Knack Technologies, Inc. (Knack), a privately held U.S. based peer-to-peer tutoring platform for higher education institutions. We do not have the ability to exercise significant influence over Knack's operating and financial policies and have elected to account for our investment at cost as it does not have a readily determinable fair value.

We did not record any impairment charges on our strategic investments during the years ended December 31, 2023, 2022 and 2021, as there were no significant identified events or changes in circumstances that would be considered an indicator for impairment. There were no observable price changes in orderly transactions for the identical or similar investments of the same issuers during the years ended December 31, 2023, 2022 and 2021.

Financial Instruments Not Recorded at Fair Value on a Recurring Basis

We report our financial instruments at fair value with the exception of the notes. The estimated fair value of the notes was determined based on the trading price of the notes as of the last day of trading for the period. We consider the fair value of the notes to be a Level 2 measurement due to the limited trading activity. The estimated fair value of the 2026 notes as of December 31, 2023 and 2022 was $202.9 million and $385.0 million, respectively. The estimated fair value of the 2025 notes as of December 31, 2023 and 2022 was $329.5 million and $640.5 million, respectively. For further information on the notes refer to Note 8, “Convertible Senior Notes.”