
October 24, 2020	Amortized Cost		Gross Unrealized Gains		Gross Unrealized and Credit Losses		Fair Value
U.S. government securities	$	2,656	$	61	$	—	$	2,717
U.S. government agency securities	178		—		—		178
Corporate debt securities	11,266		298		(27)		11,537
U.S. agency mortgage-backed securities	2,494		41		(6)		2,529
Commercial paper	1,712		—		—		1,712
Certificates of deposit	517		—		—		517
Total (1)	$	18,823	$	400	$	(33)	$	19,190


July 25, 2020	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. government securities	$	2,614	$	71	$	—	$	2,685
U.S. government agency securities	110		—		—		110
Corporate debt securities	11,549		334		(6)		11,877
U.S. agency mortgage-backed securities	1,987		49		(1)		2,035
Commercial paper	727		—		—		727
Certificates of deposit	176		—		—		176
Total	$	17,163	$	454	$	(7)	$	17,610

The following table presents the gross realized gains and gross realized losses related to available-for-sale debt investments (in millions):


	Three Months Ended
	October 24, 2020		October 26, 2019
Gross realized gains	$	15	$	12
Gross realized losses	—		(2)
Total	$	15	$	10

The following tables present the breakdown of the available-for-sale debt investments with gross unrealized losses and the duration that those losses had been unrealized at October 24, 2020 and July 25, 2020 (in millions):


	UNREALIZED LOSSES LESS THAN 12 MONTHS				UNREALIZED LOSSES 12 MONTHS OR GREATER				TOTAL
October 24, 2020	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. government securities	$	144	$	—	$	—	$	—	$	144	$	—
U.S. government agency securities	65		—		—		—		65		—
Corporate debt securities	1,008		(2)		—		—		1,008		(2)
U.S. agency mortgage-backed securities	1,076		(6)		—		—		1,076		(6)
Certificates of deposit	15		—		—		—		15		—
Total	$	2,308	$	(8)	$	—	$	—	$	2,308	$	(8)


	UNREALIZED LOSSES LESS THAN 12 MONTHS				UNREALIZED LOSSES 12 MONTHS OR GREATER				TOTAL
July 25, 2020	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. government agency securities	$	33	$	—	$	—	$	—	$	33	$	—
Corporate debt securities	1,060		(6)		3		—		1,063		(6)
U.S. agency mortgage-backed securities	265		(1)		—		—		265		(1)
Total	$	1,358	$	(7)	$	3	$	—	$	1,361	$	(7)

The following table summarizes the maturities of our available-for-sale debt investments as of October 24, 2020 (in millions):


	Amortized Cost		Fair Value
Within 1 year	$	7,480	$	7,490
After 1 year through 5 years	6,897		7,052
After 5 years through 10 years	1,943		2,109
After 10 years	9		10
Mortgage-backed securities with no single maturity	2,494		2,529
Total	$	18,823	$	19,190

Actual maturities may differ from the contractual maturities because borrowers may have the right to call or prepay certain obligations.

Our net adjustments to non-marketable equity securities measured using the measurement alternative was a net gain of $1 million and a net loss of $1 million for the first quarter of fiscal 2021 and 2020, respectively. We held equity interests in certain private equity funds of $0.7 billion as of each of October 24, 2020 and July 25, 2020, which are accounted for under the NAV practical expedient.

In the ordinary course of business, we have investments in privately held companies and provide financing to certain customers. These privately held companies and customers are evaluated for consolidation under the variable interest or voting interest entity models. We evaluate on an ongoing basis our investments in these privately held companies and our customer financings, and have determined that as of October 24, 2020, except as disclosed herein, there were no significant variable interest or voting interest entities required to be consolidated in our Consolidated Financial Statements.

The carrying value of our investments in privately held companies was $1.4 billion and $1.3 billion as of October 24, 2020 and July 25, 2020, respectively.

Of the total carrying value of our investments in privately held companies as of October 24, 2020, $0.7 billion of such investments are considered to be in variable interest entities which are unconsolidated. We have total funding commitments of $0.3 billion related to these privately held investments, some of which may be based on the achievement of certain agreed-upon milestones, and some of which are required to be funded on demand. The carrying value of these investments and the additional funding commitments collectively represent our maximum exposure related to these privately held investments.