Stockholders' Equity

3 Months Ended

Mar. 31, 2021

STOCKHOLDERS’ EQUITY

Stock Repurchase Activity

In February 2016, the Board of Directors authorized a program to repurchase up to $5.0 billion of our common stock, with no fixed expiration. There were no repurchases of common stock during the three months ended March 31, 2020 or 2021.

Stock Award Activity

Common shares outstanding plus shares underlying outstanding stock awards totaled 518 million and 519 million as of December 31, 2020 and March 31, 2021. These totals include all vested and unvested stock awards outstanding, including those awards we estimate will be forfeited. Stock-based compensation expense is as follows (in millions):


	Three Months Ended March 31,
	2020		2021
Cost of sales	$	41	$	90
Fulfillment	260		342
Technology and content	961		1,228
Marketing	332		456
General and administrative	163		190
Total stock-based compensation expense	$	1,757	$	2,306

The following table summarizes our restricted stock unit activity for the three months ended March 31, 2021 (in millions):


	Number of Units	Weighted-Average Grant-Date Fair Value
Outstanding as of December 31, 2020	15.2	$	2,004
Units granted	0.6	3,147
Units vested	(0.8)	1,270
Units forfeited	(0.5)	1,895
Outstanding as of March 31, 2021	14.5	2,096

Scheduled vesting for outstanding restricted stock units as of March 31, 2021, is as follows (in millions):


	Nine Months Ended December 31,	Year Ended December 31,
	2021	2022	2023	2024	2025	Thereafter	Total
Scheduled vesting — restricted stock units	4.8	5.3	2.8	1.4	0.1	0.1	14.5

As of March 31, 2021, there was $12.4 billion of net unrecognized compensation cost related to unvested stock-based compensation arrangements. This compensation is recognized on an accelerated basis with approximately half of the compensation expected to be expensed in the next twelve months, and has a remaining weighted-average recognition period of 1.1 years. The estimated forfeiture rate as of December 31, 2020 and March 31, 2021 was 27%. Changes in our estimates and assumptions relating to forfeitures may cause us to realize material changes in stock-based compensation expense in the future.

Changes in Stockholders’ Equity

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


	Three Months Ended March 31,
	2020		2021
Total beginning stockholders’ equity	$	62,060	$	93,404

Beginning and ending common stock	5		5

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

Beginning additional paid-in capital	33,658		42,865
Stock-based compensation and issuance of employee benefit plan stock	1,754		2,295
Ending additional paid-in capital	35,412		45,160

Beginning accumulated other comprehensive income (loss)	(986)		(180)
Other comprehensive income (loss)	(1,077)		(486)
Ending accumulated other comprehensive income (loss)	(2,063)		(666)

Beginning retained earnings	31,220		52,551

Net income	2,535		8,107
Ending retained earnings	33,755		60,658

Total ending stockholders’ equity	$	65,272	$	103,320