Capital Stock

Exercise of Options

For the six months ended June 30, 2017 and 2016, 55,780 and 323,981 shares, respectively, were exercised at a weighted-average exercise price of $2.55 and $2.58 per share, respectively, with net cash proceeds of $0.1 million and $0.8 million, respectively.

Warrants

Our outstanding warrants are exercisable for common stock at any time during their respective terms. As of June 30, 2017, the following warrants remain outstanding:



	June 30, 2017
Issue Date	Shares Subject to Warrants	Exercise Price per Share		Expiration
September 28, 2007	72,727	$	8.25	September 28, 2017

Public Offering

In April 2017, we completed a public offering in which we issued and sold 6.3 million shares of our common stock, par value $0.0001 per share, at a public offering price of $4.00 per share. We received net proceeds of approximately $23.3 million after deducting the underwriting discounts, commissions and other offering expenses of $0.5 million.

Consolidated statements of stockholders' equity as of June 30, 2017 and 2016 are as follows (in thousands):



								Accumulated
					Additional			Other						Total
	Common Stock				Paid-in			Comprehensive			Accumulated			Stockholders’
	Shares		Amount		Capital			Income (Loss)			Deficit			Equity
December 31, 2015	40,343		$	4	$	305,981		$	405		$	(283,511	)	$	22,879
Exercise of stock options	324		—		837			—			—			837
Release of stock awards	700		—		(708		)	—			—			(708		)
Employee stock-based compensation	—		—		2,631			—			—			2,631
Cancelled shares	(196	)	—		(790		)	—			—			(790		)
Total comprehensive loss	—		—		—			(434		)	(4,735		)	(5,169		)
June 30, 2016	41,171		$	4	$	307,951		$	(29	)	$	(288,246	)	$	19,680

December 31, 2016	41,255		$	4	$	311,164		$	—		$	(292,069	)	$	19,099
Exercise of stock options	56		—		142			—			—			142
Release of stock awards	688		—		(1,636		)	—			—			(1,636		)
Employee stock-based compensation	—		—		3,379			—			—			3,379
Issuance of common stock, net of issuance costs	6,325		1		23,290			—			—			23,291
Total comprehensive loss	—		—		—			102			(13,740		)	(13,638		)
June 30, 2017	48,324		$	5	$	336,339		$	102		$	(305,809	)	$	30,637