Stock-Based Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2020

Stock-Based Compensation Plan

Schedule of share-based payment award, stock options, valuation assumptions

The Company utilized the Black-Scholes valuation model for estimating the fair value of the stock options granted, with the following weighted-average assumptions for options granted in the six months ended June 30, 2020 and 2019, respectively:

	2020		2019
Risk-free interest rate	0.50	%	2.23	%
Expected volatility	122	%	126	%
Expected term in years	6.0		6.0
Dividend yield	—	%	—	%

Schedule of option activity under stock-based compensation plans

The following summary represents option activity under the Company’s stock-based compensation plans for the six months ended June 30, 2020:

		Weighted-
		Average
		Exercise
	Options	Price
	(in thousands)
Outstanding at December 31, 2019	68	$	68.56
Granted	204		5.01
Forfeited	(4)		7.19
Expired	(1)		28.54
Outstanding at June 30, 2020	267		20.98
Exercisable at June 30, 2020	45	$	88.48