The Company maintains a stock-based compensation plan, the 2011 Incentive Compensation Plan (the “2011 Plan”), as amended, to attract, motivate, retain and reward employees, directors and consultants by providing its Board or a committee of the Board the discretion to award equity incentives to these persons.

A summary of stock option activity for the nine months ended September 30, 2022 is as follows:

	Number Outstanding			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Balance as of December 31, 2021		514,693		$	5.11		4.11	$	11,850,930
Granted		—			—
Cancelled or Expired		(8,883	)		8.41
Exercised		—			—
Balance as of September 30, 2022		505,810		$	5.06		3.42	$	3,785,283
Vested or expected to vest as of September 30, 2022		505,810		$	5.06		3.42	$	3,785,283
Exercisable as of September 30, 2022		505,810		$	5.06		3.42	$	3,785,283

The aggregate intrinsic value in the table above represents the difference between the fair value of the Company’s common stock as of September 30, 2022 and the exercise price of in-the-money stock options multiplied by the number of such stock options.

The following table summarizes information about stock options outstanding as of September 30, 2022:

	Stock Options Outstanding						Stock Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
$4.36 - $7.20		445,960		3.68	$	4.37		445,960	$	4.37
$7.50 - $11.25		59,317		1.54		10.18		59,317		10.18
$11.30 - $16.95		500		1.50		11.30		500		11.30
$19.70 - $29.55		33		0.87		19.70		33		19.70
$4.36 - $29.55		505,810		3.42	$	5.06		505,810	$	5.06

As of September 30, 2022, there was no unrecognized stock-based compensation expense related to stock options.

The following is a summary of RSU activity for the nine months ended September 30, 2022:

	Number Outstanding			Weighted Average Fair Value
Unvested as of December 31, 2021		485,729		$	9.19
Granted		275,807			17.16
Vested		(212,600	)		8.75
Forfeited		(44,192	)		8.92
Unvested as of September 30, 2022		504,744		$	13.76
RSUs vested but not released		215,735		$	6.45

The fair value of the Company’s RSUs is calculated based upon the fair market value of the Company’s common stock at the date of grant. As of September 30, 2022, there was $5.6 million of unrecognized compensation expense related to unvested RSUs granted, which is expected to be recognized over a weighted average period of 2.9 years. No tax benefit was realized from RSUs for the nine months ended September 30, 2022.

The Company granted 200,000 PSUs to a certain key employee during the year ended December 31, 2020, with a grant date fair value of $6.38 per share. The PSUs are subject to the attainment of performance goals established by the Company’s Compensation Committee, the periods during which performance is to be measured, and other limitations and conditions. Performance goals are based on pre-established objectives that specify the manner of determining the number of PSUs that will vest if performance goals are attained. If the employee terminates employment, the non-vested portion of the PSUs will not vest and all rights to the non-vested portion will terminate.

The following is a summary of PSU activity for the nine months ended September 30, 2022:

	Number Outstanding
Unvested as of December 31, 2021		175,000
Granted		—
Vested		(20,000	)
Forfeited		(80,000	)
Unvested as of September 30, 2022		75,000

As of September 30, 2022, there was $0.1 million of unrecognized compensation expense related to unvested PSUs, which is expected to be recognized over a period of 0.3 years. No tax benefit was realized from PSUs for the nine months ended September 30, 2022.

The following table summarizes stock-based compensation expense related to stock options, RSUs, and PSUs included in the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended September 30, 2022 and 2021 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Cost of revenue	$	39	$	49	$	138	$	130
Research and development		239		109		780		364
Selling and marketing		223		155		606		382
General and administrative		351		259		1,041		1,151
Total	$	852	$	572	$	2,565	$	2,027

During the nine months ended September 30, 2022 and 2021, the Company repurchased 54,074 and 68,519 shares, respectively, of common stock surrendered to the Company to satisfy tax withholding obligations in connection with the vesting of RSUs issued to employees.