Stockholder's Equity

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Stockholder's Equity

11. Stockholders’ Equity

Equity Incentive Plans

Stock Options

Activity of stock options under the Company’s 2005 Stock Plan, 2011 Equity Incentive Plan and Amended and Restated 2014 Equity Incentive Plan (collectively, the "Plans") during the six months ended June 30, 2022 is set forth below:

	Number of Shares	Weighted-Average Exercise Price
Balance at December 31, 2021	1,141,814	$	27.02
Granted	10,120	197.74
Exercised	(187,856)	24.32
Canceled/Forfeited	(1,000)	22.04
Balance at June 30, 2022	963,078	29.35

Restricted Stock Units

Activity of unvested restricted stock units under the Plans during the six months ended June 30, 2022 is set forth below: 

	Number of Shares	Weighted -Average Grant Date Fair Value
Unvested at December 31, 2021	409,482	$	210.41
Granted	146,540	187.06
Released/Vested	(74,863)	176.49
Canceled/Forfeited	(15,712)	223.95
Unvested at June 30, 2022	465,447	208.05

As of June 30, 2022, 440,842 restricted stock units are expected to vest.

Stock-based Compensation

The following table sets forth the stock-based compensation expense included in the Company’s condensed consolidated statements of operations for the three and six months ended June 30, 2022 and 2021 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Cost of revenue	$	880	$	543	$	1,736	$	1,341
Research and development	1,514		1,188		2,900		2,250
Sales, general and administrative	6,392		8,072		13,043		12,607
Total	$	8,786	$	9,803	$	17,679	$	16,198

As of June 30, 2022, total unrecognized compensation cost was $76.5 million related to unvested share-based compensation arrangements which is expected to be recognized over a weighted average period of 3.0 years.

The total stock-based compensation cost capitalized in inventory was $2.0 million and $1.8 million as of June 30, 2022 and December 31, 2021, respectively.