Total stock-based compensation was $(156) and $(415) for the three months ended June 30, 2020 and 2019, respectively and $94 and $274 for the six months ended June 30, 2020 and 2019, respectively. As of June 30, 2020, there was $1,569 of unearned compensation expense related to restricted stock awards, which will be recognized over the remaining weighed average requisite service period of 22 months. As of June 30, 2020, there was $330 of unearned compensation related to time-vested stock options, which will be recognized over the remaining requisite service period of 18 months.

During the six months ended June 30, 2020, the Company granted 1,129,464 cash settled stock appreciation rights to certain employees of which 260,431 were forfeited during 2020 and 869,033 remain outstanding as of June 30, 2020. Each stock appreciation right represents the right to receive a payment measured by the increase in the fair market value of one share of the Company’s stock from the date of grant of the stock appreciation right to the date of exercise of the stock appreciation right. The cash settled stock appreciation rights vest ratably over three years and have a contractual life of 10 years. Cash settled stock appreciation rights are classified as liabilities. The Company measures the fair value of cash settled stock appreciation rights using the Black-Scholes option valuation model and remeasures the fair value of the award each reporting period until the award is settled. Compensation cost for cash settled stock appreciation rights is trued up each reporting period for changes in fair value pro-rated for the portion of the requisite service period rendered. Once vested the Company immediately recognizes compensation cost for any changes in fair value of cash settled stock appreciation rights until settlement. The estimated fair value of the cash settled stock appreciation rights as of June 30, 2020 was $470. Stock-based compensation for cash settled stock appreciation rights for the three and six months ended June 30, 2020 was not material.

The fair value of cash settled stock appreciation rights as of June 30, 2020 was estimated using the Black-Scholes option valuation model with the following assumptions:


				Expected	Risk Free
			Expected	Dividend	Interest	Fair Value
Grant Year	Grant Date	Expected Life	Volatility	Yield	Rate	Per Award

2020	1/24/2020	5.6 years	57.50%	0.00%	0.33%	$0.54
2020	3/9/2020	5.7 years	57.39%	0.00%	0.34%	$0.59
2020	4/7/2020	5.8 years	57.24%	0.00%	0.35%	$0.71