Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2017

Summary of the Company's Outstanding Common Stock Warrants

The following is a summary of the Company’s outstanding common stock warrants:


Expiration Date	Exercise Price		March 31, 2017		December 31, 2016
Expiration Date	Exercise Price		(in thousands)
04/16/18	$	3.40		1,460		1,460
09/23/18	$	2.80		147		147
02/18/19	$	2.75		1,872		1,872
02/11/19	$	2.56		293		293
08/28/19	$	2.90		2,700		2,700
06/14/17	$	3.70		216		216
03/25/20	$	1.71		2,920		2,920
03/20/20	$	2.13		234		234

Total Warrants Outstanding				9,842		9,842

Summary of the Company's Stock Option Activity under Equity Incentive Plans

The following is a summary of the Company’s stock option activity under its equity incentive plans:


	Options Available for Grant			Options Outstanding			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life		Aggregate Intrinsic Value
	(in thousands)								(years)		(in thousands)
Balance at December 31, 2016		549			4,177		$	1.47		8.14
Options authorized		2,000
Options granted		(2,120	)		2,120		$	0.40
Options forfeited		361			(361	)	$	1.19

Balance at March 31, 2017		790			5,936		$	1.11		8.59	$	933


Vested and exercisable at March 31, 2017					1,557		$	1.68		7.64	$	55

Vested and expected to vest at March 31, 2017					4,394		$	1.04		8.41	$	600

Unvested at March 31, 2017					4,379		$	0.91

Weighted-Average Assumptions

The fair values for the stock options granted were estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the periods indicated:


	Three months ended March 31,
	2017			2016
Risk-free interest rate		2.0	%		1.5	%
Expected life (years)		6.3			6.0
Expected volatility		89	%		89	%
Dividend yield		0	%		0	%

- 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