Stock-Based Compensation

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Stock Option Plans

The Company adopted a stock plan in 2006 (the "2006 Plan"), which provided for the granting of incentive stock options, non-qualified stock options, stock appreciation rights, deferred stock awards, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights. In October 2014, the 2006 Plan was terminated, and the Company adopted a new plan (the "2014 Plan"). No further grants or awards were subsequently made under the 2006 Plan. A total of 3,662 options were awarded from the 2006 Plan and as of December 31, 2021, 364 of these options remain outstanding and eligible for future exercise.

The 2014 Plan provides for the granting of incentive stock options, non-qualified stock options, stock appreciation rights, deferred stock awards, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights. In May 2018, the 2014 Plan was terminated, and the Company adopted a new 2018 Stock Option and Incentive Plan, which was amended in May 2020 (the "2018 Stock Plan"). A total of 16,896 options were awarded from the 2014 Plan and as of December 31, 2021, 16,108 of these options remain outstanding and eligible for future exercise. A total of 3,619 restricted stock awards were awarded from the 2014 Plan and as of December 31, 2021, all of these restricted stock awards have vested. No further stock awards may be issued from the 2014 Plan.

The 2018 Stock Plan initially reserved for issuance 32,500 shares of the Company's common stock for grants of incentive stock options, non-qualified stock options, stock grants and other stock-based awards. In accordance with the terms of the 2018 Stock Plan, beginning on the first day in January 2019, the Company's Board of Directors has annually approved the addition of shares to the 2018 Stock Plan in amounts equal to 5% of the outstanding shares of the Company's common stock on the day prior to the increase. Total shares added to the 2018 Plan from these annual additions through January 2022 have amounted to 469,998. At its annual meetings of stockholders held on May 19, 2020 and May 24, 2021, stockholders approved amendments to add 250,000 and 300,000 more shares, respectively, to the 2018 Plan. As of December 31, 2021, a total of 745,184 options and restricted stock awards have been issued from the 2018 Stock Plan, and as of that date, 715,244 options and restricted stock awards remain outstanding.

Expense Information for Stock Awards

The Company recognized stock-based compensation expense, related to employee stock awards, including awards to non-employees and members of the Board of Directors, of $1,675 and $739 for the years ended December 31, 2021 and 2020, respectively. At December 31, 2021, there was approximately $4,036 of stock-based compensation expense related to unvested awards not yet recognized which is expected to be recognized over a weighted average period of 2.96 years.

Stock Options

Options granted under the 2006 Plan, 2014 Plan and 2018 Stock Plan generally vest ratably over periods of one to four years from the date of hire for new employees, the date of award for existing employees, or date of commencement of services with the Company for non-employees, and generally expire ten years from the date of issuance. The Company's policy is to issue new shares upon the exercise of stock options.

A summary of the activity related to the shares of common stock covered by outstanding options is as follows:


	Number of Shares	Weighted Average Exercise Price		Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance at December 31, 2020	339,108	$	32.39
Granted	386,017	10.08
Exercised	—	—
Forfeited	(1,509)	12.92
Expired	(851)	1,131.62
Balance at December 31, 2021	722,765	19.22		8.79	$	—
Vested and expected to vest at December 31, 2021	722,765	19.22		8.79	$	—
Exercisable at December 31, 2021	213,156	43.15		8.07	$	—

The weighted average grant date fair value per share of options granted during fiscal years 2021 and 2020, was $8.99 and $5.31, respectively. No options were exercised during 2021 and 2020, and therefore the intrinsic value for exercised options during the two years was not applicable. The weighted average remaining contractual term for options outstanding as of December 31, 2021 was 8.79 years.

For the years ended December 31, 2021, and 2020, the Company determined the fair value of stock options using the Black-Scholes option pricing model with the following assumptions for option grants, respectively:


	Year Ended December 31,
	2021	2020
Expected dividend yield	—	—
Risk-free rate	0.7% - 1.7%	0.5% - 1.9%
Expected option term (in years)	6.1 - 10.0	6.1 - 10.0
Volatility	118% - 128%	111% - 129%

The Company determined its volatility assumption based on actual market price fluctuations experienced during its trading history. The risk-free interest rate used for each grant is equal to the U.S. Treasury yield curve in effect at the time of grant for instruments with a term similar to the expected life of the related option. The expected term of the options is based upon evaluation of historical and expected future exercise behavior.

The stock price volatility and expected terms utilized in the calculation involve management's best estimates at that time, both of which impact the fair value of the option calculated under the Black-Scholes methodology and, ultimately, the expense that will be recognized over the life of the option. The accounting standard for stock-based compensation requires that the Company recognize compensation expense for only the portion of options that vest. The Company recognizes stock option forfeitures resulting from award terminations in the period in which the forfeiture occurs.

Restricted Stock Units ("RSUs")

The Company records stock compensation expense for RSUs on a straight-line basis over their requisite service period, which approximates the vesting period, based on each RSU's award date market value. As RSUs vests, the Company withholds a number of shares from its employees with an aggregate fair market value equal to the minimum tax withholding amount (unless the employee makes other arrangements for payment of the tax withholding) from the common stock issuable at the vest date. The Company then pays the minimum required income tax for the employees. During the years ended December 31, 2021 and December 31, 2020, the Company withheld vested shares with a fair value of $102 and $17, respectively, to pay for minimum tax withholding associated with RSU vesting.

A summary of RSU activity for the year ended December 31, 2021 is as follows:


	Number of RSUs	Weighted Average Remaining Contractual Life (years)
Outstanding at December 31, 2020	8,500
Awarded	18,862
Released	(17,932)
Forfeited	—
Outstanding at December 31, 2021	9,430	0.16

Weighted average remaining recognition period (years)	0.16