The changes in the carrying amount of goodwill during the three months ended March 31, 2024 were as follows (in millions):


	Total

Balance as of December 31, 2023	$	2,432

Effects of foreign currency translation	(46)
Balance as of March 31, 2024	$	2,386

Intangible assets, net consisted of the following as of December 31, 2023 (in millions):


	Weighted-average Remaining Useful Life (in years)	Gross Carrying Value		Accumulated Amortization		Net Carrying Value

Existing technology	4.3	$	241	$	(117)	$	124
Merchant relationships	9.1	302		(56)		246
Courier relationships	—	12		(12)		—
Customer relationships	1.4	123		(69)		54
Trade name and trademarks	8.4	286		(51)		235
Balance as of December 31, 2023		$	964	$	(305)	$	659

Intangible assets, net consisted of the following as of March 31, 2024 (in millions):


	Weighted-average Remaining Useful Life (in years)	Gross Carrying Value		Accumulated Amortization		Net Carrying Value

Existing technology	4.1	$	236	$	(123)	$	113
Merchant relationships	8.9	295		(62)		233
Customer relationships	1.2	120		(77)		43
Trade name and trademarks	8.1	279		(57)		222
Assembled workforce in asset acquisition	3.0	10		—		10
Balance as of March 31, 2024		$	940	$	(319)	$	621

Amortization expense associated with intangible assets was $33 million and $31 million for the three months ended March 31, 2023 and 2024, respectively.

The estimated future amortization expense of intangible assets as of March 31, 2024 is as follows (in millions):


Year Ending December 31,	Amortization Expense

Remainder of 2024	$	94
2025	101
2026	83
2027	79
2028	63
Thereafter	201
Total estimated future amortization expense	$	621