Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2017



	Options Outstanding
	Number of Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in thousands)
Balance, December 31, 2015	1,685,248	$	37.38	8.72	$	—
Granted	4,858,460		7.12
Exercised	(1,109)		36.63
Forfeited	(105,084)		32.09
Balance, December 31, 2016	6,437,515	$	8.32	9.28	$	2,227,268
Granted	2,853,000		3.69
Exercised	—		—
Forfeited	(793,643)		6.23
Balance, December 31, 2017	8,496,872	$	6.96	8.83	$	—
Options vested and exercisable, December 31, 2017	3,969,407	$	9.76	8.04	$	—

Weighted-average Fair Value of Stock Option Awards Granted



	Year Ended
	December 31, 2017	December 31, 2016	December 31, 2015
Weighted average fair value of grants	$2.44	$7.12	$20.67
Expected volatility	74.48% - 74.92%	74.98% - 79.35%	77.23% - 93.85%
Risk-free interest rate	1.87% - 2.22%	1.15% - 2.20%	1.54% - 1.93%
Expected life	5.5 - 6.0 years	5.0 - 6.0 years	5.2 - 6.0 years
Expected dividend yield	0%	0%	0%

Warrants Outstanding



	Warrants	Weighted Average Exercise Price
Balance, December 31, 2015	710,801	$	46.64
Granted	617,651		10.20
Balance, December 31, 2016	1,328,452	$	29.70
Granted	13,394,338		3.58
Exercised	(22,800)		3.35
Forfeited	—		—
Balance, December 31, 2017	14,699,990	$	5.94

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

+ References + Details