As of December 31, 2013 | As of December 31, 2012 | |||||||||||||||||||
Issued in Connection With: | Exercise Price | Expiration Date | Number of Warrants | Common Stock Warrant Liability | Number of Warrants | Common Stock Warrant Liability | ||||||||||||||
March 2013 financing | $ | 0.79 | September 12, 2018 | 3,022,725 | $ | 7,859,085 | — | $ | — | |||||||||||
December 2011 financing | $ | 0.65 | December 6, 2016 | — | — | 5,774,784 | 2,078,921 | |||||||||||||
January 2011 financing | $ | 1.40 | January 27, 2016 | 6,695,000 | 11,381,498 | 10,565,200 | 779,711 | |||||||||||||
July 2009 financing | $ | 3.38 | July 1, 2014 | 333,333 | 300,000 | 333,333 | 1,267 | |||||||||||||
Warrants assumed in June 2009 Merger | $1.02-$1.28 | August 1, 2015- April 28, 2016 | 4,008,202 | — | 4,920,527 | — | ||||||||||||||
Total | 14,059,260 | $ | 19,540,583 | 21,593,844 | $ | 2,859,899 | ||||||||||||||