Stock-Based Compensation - (Tables)

The Company recognized total stock-based compensation expense during the years ended December 31, 2020 and 2019 as follows (table in thousands):

A summary of the Company’s restricted stock awards during the years ended December 31, 2020 and 2019 is as follows:


	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2019	146,800	$	5.70

Unvested at December 31, 2019	146,800	$	5.70

Unvested at December 31, 2020	146,800	$	5.70

A summary of the Company’s service based restricted stock units during the year ended December 31, 2020 and 2019 is as follows:


	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2019	472,959	$	4.32
Granted	244,063	4.09
Forfeited	(28,916)	4.32
Vested	(224,320)	4.19
Unvested at December 31, 2019	463,786	4.26
Granted	208,993	2.00
Forfeited	(159,724)	4.26
Vested	(247,561)	4.30
Unvested at December 31, 2020	265,494	$	2.60

A summary of the Company’s performance based restricted stock units during the year ended December 31, 2020 and 2019 is as follows:


	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2020	988,958	$	4.48




Forfeited	(988,958)	$	4.48
Unvested at December 31, 2020	—	$	—


	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2019	988,958	$	4.48
Unvested at December 31, 2019	988,958	$	4.48

The fair value of the service based stock options granted for the years ended December 31, 2020 and 2019 were based on the following assumptions:


	December 31,
	2020	2019
Exercise price	$0.92 - $2.90	$1.91 - $6.55
Expected stock price volatility	68.2% - 75.8%	67.5% - 70.3%
Risk-free interest rate	0.31% - 1.70%	1.40% - 2.60%
Term (years)	5.5 - 6.0	3.4 - 6.5

The fair value of the performance-based stock options granted for the year ended December 31, 2020 were based on the following assumptions:



Expected stock price volatility			74.4%
Risk-free interest rate			0.4%
Dividend yield rate			—
Term (years)			5.7

A summary of the performance based stock options granted for the year ended December 31, 2020, is as follows:


	Number of Shares	Weighted Average Exercise Price
Outstanding at January 1, 2019	388,125	$	4.70
Outstanding at December 31, 2019	388,125	$	4.70
Granted	750,000	$	2.20
Forfeited	(388,125)	$	(4.70)

Outstanding at December 31, 2020	750,000	$	2.20

Exercisable at December 31, 2020	—	$	—