| | | as of December 31, 2013 | | |||||
| | | Number of | | Weighted | | Weighted | | |
| | | outstanding | | Average | | Average | | |
| | | warrants | | Exercise Price | | Life (years) | | |
| Outstanding at January 1, 2013 | | 7,603,795 | | $ | 0.91 | | 4.87 | |
| Issued in a private placement | | 2,490,000 | | $ | 1.25 | | 4.58 | |
| Exercised | | (80,291) | | $ | 0.49 | | 5.12 | |
| Outstanding at December 31, 2013 | | 10,013,504 | | $ | 1.00 | | 4.04 | |
| | | as of December 31, 2012 | | |||||
| | | Number of | | Weighted | | Weighted | | |
| | | outstanding | | Average | | Average | | |
| | | warrants | | Exercise Price | | Life (years) | | |
| Outstanding at January 1, 2012 | | 4,880,636 | | $ | 0.91 | | 5.69 | |
| A-3 warrants exchanged to A-7 | | (4,807,711) | | $ | 0.91 | | 4.86 | |
| A-7 warrants granted in exchange to A-3 | | 7,530,870 | | $ | 0.91 | | 4.86 | |
| Outstanding at December 31, 2012 | | 7,603,795 | | $ | 0.91 | | 4.87 | |