Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Stockholders' Equity

STOCKHOLDERS’ EQUITY

Preferred Stock

We have authorized 500 million shares of $0.01 par value preferred stock. No preferred stock was outstanding for any year presented.

Common Stock

Common shares outstanding plus shares underlying outstanding stock awards totaled 512 million, 518 million, and 523 million, as of December 31, 2019, 2020, and 2021. These totals include all vested and unvested stock awards outstanding, including those awards we estimate will be forfeited.

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 in 2019, 2020, or 2021. During the period from January 1, 2022 through February 2, 2022, we repurchased 0.5 million shares of our common stock for $1.3 billion.

Stock Award Plans

Employees vest in restricted stock unit awards over the corresponding service term, generally between two and five years.

Stock Award Activity

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

	Year Ended December 31,
	2019		2020		2021
Cost of sales	$	149	$	283	$	540
Fulfillment	1,182		1,357		1,946
Technology and content	3,725		5,061		6,645
Marketing	1,135		1,710		2,530
General and administrative	673		797		1,096
Total stock-based compensation expense (1)	$	6,864	$	9,208	$	12,757

___________________

(1)The related tax benefits were $1.4 billion, $1.9 billion, and $2.7 billion for 2019, 2020, and 2021.

The following table summarizes our restricted stock unit activity (in millions):

	Number of Units	Weighted Average Grant-Date Fair Value
Outstanding as of January 1, 2019	15.9	$	1,024
Units granted	6.7	1,808
Units vested	(6.6)	827
Units forfeited	(1.7)	1,223
Outstanding as of December 31, 2019	14.3	1,458
Units granted	8.0	2,373
Units vested	(5.8)	1,239
Units forfeited	(1.3)	1,642
Outstanding as of December 31, 2020	15.2	2,004
Units granted	6.3	3,348
Units vested	(5.4)	1,704
Units forfeited	(2.1)	2,314
Outstanding as of December 31, 2021	14.0	2,684

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

	Year Ended
	2022	2023	2024	2025	2026	Thereafter	Total
Scheduled vesting — restricted stock units	5.4	5.2	2.2	0.9	0.1	0.2	14.0

As of December 31, 2021, there was $16.6 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, 2019, 2020, and 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.

During 2019, 2020, and 2021, the fair value of restricted stock units that vested was $11.7 billion, $15.5 billion, and $18.2 billion.

Common Stock Available for Future Issuance

As of December 31, 2021, common stock available for future issuance to employees is 97 million shares.