Stockholders' Equity

3 Months Ended

Mar. 31, 2022

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Stockholders’ Equity

As of March 31, 2022, the 2005 Incentive Plan, as amended, has a total reserve of 27,783,379 shares of which 3,752,174 shares are available for issuance.

Summary of Stock-Based Compensation Expense

The stock-based compensation related to our stock-based awards and employee stock purchase plan for the three months ended March 31, 2022 and 2021 is as follows (in thousands):

	Three Months Ended March 31,
	2022		2021
Cost of net revenues	$	1,514	$	1,306
Selling, general and administrative	24,725		21,844
Research and development	5,382		4,091
Total stock-based compensation	$	31,621	$	27,241

Restricted Stock Units (“RSUs”)

The fair value of RSUs is based on our closing stock price on the date of grant. RSUs granted generally vest over a period of four years. A summary for the three months ended March 31, 2022 is as follows:

	Number of Shares Underlying RSUs (in thousands)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Unvested as of December 31, 2021	492	$	369.17
Granted	217	499.14
Vested and released	(176)	330.33
Forfeited	(11)	423.61
Unvested as of March 31, 2022	522	$	435.22	1.8	$	227,614

As of March 31, 2022, we expect to recognize $192.2 million of total unamortized compensation costs, net of estimated forfeitures, related to RSUs over a weighted average period of 2.8 years.

Market-Performance Based Restricted Stock Units (“MSUs”)

We grant MSUs to members of senior management. Each MSU represents the right to one share of Align’s common stock. The actual number of MSUs which will be eligible to vest will be based on the performance of Align’s stock price relative to the performance of a stock market index over the vesting period. MSUs vest over a period of three years and the maximum number of eligible to vest in the future is 250% of the MSUs initially granted.

The following table summarizes the MSU performance for the three months ended March 31, 2022: 

	Number of Shares Underlying MSUs (in thousands)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Unvested as of December 31, 2021	174	$	551.57
Granted 1	101	607.96
Vested and released	(128)	396.10
Forfeited	(3)	744.39
Unvested as of March 31, 2022	144	$	725.73	1.7	$	62,814

1 Includes MSUs vested during the period above 100% of the grant as actual shares released is based on Align's stock performance over the vesting period

As of March 31, 2022, we expect to recognize $62.3 million of total unamortized compensation costs, net of estimated forfeitures, related to MSUs over a weighted average period of 1.7 years.

Employee Stock Purchase Plan

As of March 31, 2022, we have 2,156,295 shares available for future issuance under our Amended and Restated 2010 Employee Stock Purchase Plan (the “2010 Purchase Plan”).

The fair value of the option component of the 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:

	Three Months Ended March 31,
	2022			2021
Expected term (in years)	1.5			1.0
Expected volatility	48.6		%	58.8		%
Risk-free interest rate	1.0		%	0.1		%
Expected dividends	—			—
Weighted average fair value at grant date	$	196.97		$	202.74

As of March 31, 2022, we expect to recognize $20.0 million of total unamortized compensation costs related to future employee stock purchases over a weighted average period of 1.0 year.