Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2020

Stock-based compensation expense is as follows (in millions):


	Three Months Ended June 30,						Six Months Ended June 30,
	2019		2020		2019		2020
Cost of sales	$	43	$	76	$	67	$	118
Fulfillment	360		417		594		677
Technology and content	1,077		1,421		1,752		2,382
Marketing	307		456		516		787
General and administrative	184		231		316		394
Total stock-based compensation expense	$	1,971	$	2,601	$	3,245	$	4,358

Nonvested Restricted Stock Units Activity

The following table summarizes our restricted stock unit activity for the six months ended June 30, 2020 (in millions):


	Number of Units	Weighted-Average Grant-Date Fair Value
Outstanding as of December 31, 2019	14.3	$	1,458
Units granted	5.7	2,063
Units vested	(3.1)	1,187
Units forfeited	(0.7)	1,493
Outstanding as of June 30, 2020	16.2	1,721

Scheduled Vesting Restricted Stock Unit Activity

Scheduled vesting for outstanding restricted stock units as of June 30, 2020, is as follows (in millions):


	Six Months Ended December 31,	Year Ended December 31,
	2020	2021	2022	2023	2024	Thereafter	Total
Scheduled vesting—restricted stock units	2.7	5.8	5.1	2.0	0.5	0.1	16.2

Changes in Stockholders Equity

The following table shows the changes in stockholders’ equity (in millions):


	Three Months Ended June 30,						Six Months Ended June 30,
	2019		2020		2019		2020
Total beginning stockholders’ equity	$	48,410	$	65,272	$	43,549	$	62,060

Beginning and ending common stock	5		5		5		5

Beginning and ending treasury stock	(1,837)		(1,837)		(1,837)		(1,837)

Beginning additional paid-in capital	28,059		35,412		26,791		33,658
Stock-based compensation and issuance of employee benefit plan stock	1,976		2,605		3,244		4,359
Ending additional paid-in capital	30,035		38,017		30,035		38,017

Beginning accumulated other comprehensive income (loss)	(1,010)		(2,063)		(1,035)		(986)
Other comprehensive income (loss)	50		608		75		(469)
Ending accumulated other comprehensive income (loss)	(960)		(1,455)		(960)		(1,455)

Beginning retained earnings	23,193		33,755		19,625		31,220
Cumulative effect of changes in accounting principles (1)	—		—		7		—
Net income	2,625		5,243		6,186		7,778
Ending retained earnings	25,818		38,998		25,818		38,998

Total ending stockholders’ equity	$	53,061	$	73,728	$	53,061	$	73,728

___________________

(1)We recorded cumulative effect adjustments related to the new lease standard in Q1 2019 and the new measurement of credit losses standard in Q1 2020.