The following table summarizes warrant activity for the two years ended December 31, 2013:
| Shares |
Weighted-Average Exercise Price |
Weighted-Average Remaining Contractual Terms (Years) |
Aggregate Intrinsic Value |
|||||||||||||
| Outstanding at December 31, 2011 | 2,006,870 | $ | 4.32 | |||||||||||||
| Granted | - | - | ||||||||||||||
| Exercised | (574,622 | ) | $ | 1.61 | ||||||||||||
| Forfeited or expired | (1,114,995 | ) | $ | 6.26 | ||||||||||||
| Outstanding at December 31, 2012 | 317,253 | $ | 2.40 | |||||||||||||
| Granted | - | - | ||||||||||||||
| Exercised | (215,290 | ) | $ | 2.45 | ||||||||||||
| Forfeited or expired | - | - | ||||||||||||||
| Outstanding at December 31, 2013 | 101,963 | $ | 2.30 | 1.9 | $ | 579,000 | ||||||||||
| Exercisable at December 31, 2013 | 101,963 | $ | 2.30 | 1.9 | $ | 579,000 | ||||||||||