Stock-Based Compensation

6 Months Ended

Jun. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

(9) Stock-Based Compensation

Columbia recorded stock-based compensation expense of $0.2 million for both three month periods ended June 30, 2013 and 2012. Columbia recorded stock-based compensation expense of $0.3 million and $0.5 million for the six months ended June 30, 2013 and 2012, respectively. Stock-based compensation is included in the accompanying consolidated statements of operations as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Cost of revenues	$	4,868	$	2,951	$	4,868	$	10,039
Research and development		—		10,765		—		61,250
General and administrative		162,205		154,830		268,172		416,692
Total	$	167,073	$	168,546	$	273,040	$	487,981

Columbia granted 710,000 and 835,000 stock options during the six months ended June 30, 2013 and 2012, respectively. Columbia has elected to use the Black-Scholes model to determine the weighted average fair value of options. The weighted average fair value of the options granted during the six months ended June 30, 2013 and 2012 was $0.44 and $0.50, respectively, using the following assumptions:

	Six Months Ended June 30,
	2013			2012
Risk free interest rate		0.71%-0.76	%		0.82	%
Expected term		4.75			4.75
Dividend yield		—			—
Expected volatility		96.52%-97.02	%		105.72	%

Option-pricing models require the input of various subjective assumptions, including the option’s expected life and the price volatility of the underlying stock. Columbia’s estimated expected stock price volatility is based on its own historical volatility. Columbia’s expected term of options granted in the six months ended June 30, 2013 and 2012, was derived from the simplified method. The risk-free rate for the expected term of the option is based on the U.S. Treasury yield curve in effect at the time of grant.