| Summary of stock based awards |
| | | | | | | | | | | | | | | | | | | Shares | | | Weighted average exercise price | | | Weighted average remaining term | | | Aggregate fair value | | Options | | | | | | | | | | | | | | | | | Outstanding as of December 31, 2014 | | | 5,804,594 | | | $ | 4.57 | | | | 4.64 | | | $ | 8,410 | | Vested at December 31, 2014 | | | 1,643,665 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2014 | | | 1,500,476 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (159,828 | ) | | | — | | | | — | | | | (193 | ) | Granted | | | 1,000,000 | | | | 1.2 | | | | — | | | | 552 | | Outstanding as of December 31, 2015 | | | 6,644,766 | | | $ | 4.09 | | | | 4.23 | | | $ | 8,769 | | Vested at December 31, 2015 | | | 730,592 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2015 | | | 730,592 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (348,520 | ) | | | — | | | | — | | | | — | | Granted | | | 2,500,000 | | | | 1.2 | | | | — | | | | — | | Outstanding as of December 31, 2016 | | | 8,796,246 | | | $ | 3.20 | | | | 4.41 | | | $ | 9,804 | | Vested at December 31, 2016 | | | 1,210,824 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2016 | | | 1,210,824 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (891,670) | | | | — | | | | — | | | | — | | Granted | | | — | | | | — | | | | — | | | | — | | Outstanding as of December 31, 2017 | | | 7,904,576 | | | $ | 2.98 | | | | 3.80 | | | $ | 7,539 | | Restricted stock and restricted stock units | | | | | | | | | | | | | | | | | Non Vested as of December 31, 2014 | | | 1,997,344 | | | $ | — | | | | 2.00 | | | $ | 10,899 | | Granted | | | 2,540,000 | | | | — | | | | — | | | | 3,048 | | Vested | | | (812,847 | ) | | | — | | | | — | | | | (5,746 | ) | Forfeited or expired | | | (3,538 | ) | | | — | | | | — | | | | (15 | ) | Non Vested as of December 31, 2015 | | | 3,720,959 | | | $ | — | | | | 2.45 | | | $ | 8,186 | | Granted | | | 2,540,000 | | | | — | | | | — | | | | 3,048 | | Vested | | | (1,755,017 | ) | | | — | | | | — | | | | (5,122 | ) | Forfeited or expired | | | (3,408 | ) | | | — | | | | — | | | | (12 | ) | Non Vested as of December 31, 2016 | | | 4,502,534 | | | $ | — | | | | 2.55 | | | $ | 6,100 | | Granted | | | 4,353,975 | | | | — | | | | — | | | | 42 | | Vested | | | (1,839,195) | | | | — | | | | — | | | | (2,630 | ) | Forfeited or expired | | | — | | | | — | | | | — | | | | — | | Non Vested as of December 31, 2017 | | | 7,017,314 | | | $ | — | | | | 3.21 | | | $ | 3,512 | |
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