Share-Based Compensation

Share-based Compensation

We utilize share-based compensation in the form of stock options, warrants and restricted stock. The following table summarizes the components of share-based compensation expense for the three months ended March 31, 2016 and 2015 (in thousands):



	Three Months Ended March 31,
	2016		2015
Cost of goods sold	$	124.3	$	116.9
Research and development	92.3		422.7
Selling, general and administrative	634.6		3,176.1
Total share-based compensation expense	$	851.2	$	3,715.7

Total compensation cost related to nonvested awards not yet recognized and the weighted-average periods over which the awards are expected to be recognized at March 31, 2016 were as follows (in thousands):



	Stock Options		Restricted Stock
Unrecognized compensation cost	$	2,101.8	$	624.4
Expected weighted-average period in years of compensation cost to be recognized	2.21		2.25

Total fair value of shares vested and the weighted average estimated fair values of shares granted for the three months ended March 31, 2016 and 2015 were as follows (in thousands):



	Stock Options				Warrants
	Three Months Ended March 31,				Three Months Ended March 31,
	2016		2015		2016		2015
Total fair value of shares vested	$	994.1	$	2,706.2	$	—	$	6.8
Weighted average estimated fair value of shares granted	$	0.41	$	2.44	$	—	$	—

Valuation Assumptions

The fair value of stock options and warrants at the date of grant was estimated using the Black-Scholes option pricing model. The expected volatility is based upon historical volatility of the Company’s stock. The expected term for the options is based upon observation of actual time elapsed between date of grant and exercise of options for all employees. The expected term for the warrants is based upon the contractual term of the warrants.