As of December 31, 2023 and March 31, 2024, our cash, cash equivalents, restricted cash, and marketable securities primarily consisted of cash, AAA-rated money market funds, U.S. and foreign government and agency securities, other investment grade securities, and marketable equity securities. Cash equivalents and marketable securities are recorded at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. To increase the comparability of fair value measures, the following hierarchy prioritizes the inputs to valuation methodologies used to measure fair value:

Level 2—Valuations based on observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data.

Level 3—Valuations based on unobservable inputs reflecting our own assumptions, consistent with reasonably available assumptions made by other market participants. These valuations require significant judgment.

We measure the fair value of money market funds and certain marketable equity securities based on quoted prices in active markets for identical assets or liabilities. Other marketable securities were valued either based on recent trades of securities in inactive markets or based on quoted market prices of similar instruments and other significant inputs derived from or corroborated by observable market data.

The following table summarizes, by major security type, our cash, cash equivalents, restricted cash, and marketable securities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in millions):


	December 31, 2023		March 31, 2024
	Total Estimated Fair Value		Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Estimated Fair Value
Cash	$	11,706	$	11,633	$	—	$	—	$	11,633
Level 1 securities:
Money market funds	39,160		28,676		—		—		28,676
Equity securities (1)	4,658								2,575
Level 2 securities:
Foreign government and agency securities	505		19		—		—		19
U.S. government and agency securities	1,699		2,641		1		(89)		2,553
Corporate debt securities	27,805		38,636		—		(146)		38,490
Asset-backed securities	1,646		1,554		—		(45)		1,509
Other debt securities	104		102		—		(3)		99

	$	87,283	$	83,261	$	1	$	(283)	$	85,554
Less: Restricted cash, cash equivalents, and marketable securities (2)	(503)								(480)
Total cash, cash equivalents, and marketable securities	$	86,780							$	85,074

(2)We are required to pledge or otherwise restrict a portion of our cash, cash equivalents, and marketable debt securities primarily as collateral for real estate, amounts due to third-party sellers in certain jurisdictions, debt, and standby and trade letters of credit. We classify cash, cash equivalents, and marketable debt securities with use restrictions of less than twelve months as “Accounts receivable, net and other” and of twelve months or longer as non-current “Other assets” on our consolidated balance sheets. See “Note 4 — Commitments and Contingencies.”

The following table summarizes the remaining contractual maturities of our cash equivalents and marketable debt securities as of March 31, 2024 (in millions):


	Amortized Cost		Estimated Fair Value
Due within one year	$	66,539	$	66,481
Due after one year through five years	3,810		3,652
Due after five years through ten years	404		389
Due after ten years	875		824
Total	$	71,628	$	71,346

We hold equity warrants giving us the right to acquire stock of other companies. As of December 31, 2023 and March 31, 2024, these warrants had a fair value of $2.2 billion and $2.1 billion, with gains and losses recognized in “Other income (expense), net” on our consolidated statements of operations. These warrants are classified as Level 2 and 3 assets.

As of December 31, 2023 and March 31, 2024, equity investments not accounted for under the equity-method and without readily determinable fair values had a carrying value of $754 million and $801 million, with adjustments recognized in “Other income (expense), net” on our consolidated statements of operations.

In Q3 2023, we invested in a $1.25 billion note from Anthropic, PBC, which is convertible to equity. In Q1 2024, we invested $2.75 billion in a second convertible note. The notes are classified as available for sale and reported at fair value with unrealized gains and losses included in “Accumulated other comprehensive income (loss).” The notes are classified as Level 3 assets. We also have a commercial arrangement primarily for the provision of AWS cloud services, which includes the use of AWS chips.

The following table provides a reconciliation of the amount of cash, cash equivalents, and restricted cash reported within the consolidated balance sheets to the total of the same such amounts shown in the consolidated statements of cash flows (in millions):


	December 31, 2023		March 31, 2024
Cash and cash equivalents	$	73,387	$	72,852
Restricted cash included in accounts receivable, net and other	497		474
Restricted cash included in other assets	6		6
Total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows	$	73,890	$	73,332