The following table is a reconciliation of the warrant liability measured at fair value using level 3 inputs (in thousands):
Warrant Liability | ||||
Balance at December 31, 2011 |
$ | 9,209 | ||
Exercise of common stock warrants during 2012 |
(27,867 | ) | ||
Change in fair value of common stock warrants during 2012 |
51,216 | |||
|
|
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Balance at December 31, 2012 |
$ | 32,558 |