WARRANTS (Tables)

6 Months Ended

Jun. 30, 2014

Reconciliation of Change in Value of Company's Warrants Liability

The following table summarizes the reconciliation of the change in value of the Company’s liability classified warrants for each of the periods indicated:

	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2014			2013			2014			2013
	(in thousands)
Balance at beginning of the period	$	9,213		$	91,077		$	9,006		$	65,193
Increase in value of warrants		3,784			1,945			7,035			28,851
Reclassification to stockholders’ equity upon exercise of warrants		(3,171	)		(13,906	)		(6,215	)		(14,928	)
Balance at end of the period	$	9,826		$	79,116		$	9,826		$	79,116

Summary of Warrant Activity

The following table summarizes the Company’s warrant activity for each of the periods indicated:

	For the Three Months Ended June 30,										For the Six Months Ended June 30,
	2014					2013					2014					2013
	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Warrants outstanding at beginning of the period		633,740		$	9.92		3,093,676		$	8.49		791,508		$	10.50		3,127,618		$	8.48
Exercised		(132,246	)		8.87		(464,753	)		8.94		(290,014	)		9.80		(498,695	)		8.89
Warrants outstanding at end of the period		501,494		$	10.20		2,628,923		$	8.41		501,494		$	10.20		2,628,923		$	8.41
Warrants exercisable at end of the period		501,494		$	10.20		2,628,923		$	8.41		501,494		$	10.20		2,628,923		$	8.41

Summary of Company's Warrants Outstanding

The following table summarizes the Company’s warrants outstanding at June 30, 2014:

Issue Date	Exercise Price		Outstanding Warrants		Expiration Date
1/30/2009	$	6.96		65,325		7/30/2014
8/25/2009	$	10.68		436,169		8/31/2014

Warrant [Member]

Schedule of Assumptions

The following table reflects the assumptions for each of the periods indicated:

	As of June 30, 2014	As of December 31, 2013
Risk-free interest rate (1)	Less than 0.1%	0.1%
Expected dividend yield (2)	0%	0%
Expected lives (3)	0.1 – 0.2 years	0.6 – 0.7 years
Expected volatility (4)	48.2 – 62.1%	95.5%
Shares underlying warrants classified as liabilities	501,494	791,508
Market value of stock at beginning of the period	$20.37	$25.80
Market value of stock at end of the period	$29.79	$20.37

(1) The risk-free interest rate is estimated using an average of U.S. Treasury bill interest rates that correlate to the prevailing interest rates at the valuation date.

(2) The expected dividend yield is zero as the Company has not paid any dividends to date and does not expect to pay dividends prior to the expiration of the warrants.

(3) The expected lives are based on the remaining contractual lives of the related warrants at the valuation date.

(4) The expected volatility is estimated using implied volatility in exchange-traded options associated with the Company’s common stock.