Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] |
The following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value on a recurring basis: | | As of March 31, 2017 | | | | Level 1 | | Level 2 | | Level 3 | | Balance | | | | | | | | | | | | | | | | Financial Assets | | | | | | | | | | | | | | Cash equivalents | | $ | 16,160,498 | | $ | - | | $ | - | | $ | 16,160,498 | | Total financial assets measured at fair value | | $ | 16,160,498 | | $ | - | | $ | - | | $ | 16,160,498 | | | | As of December 31, 2016 | | | | Level 1 | | Level 2 | | Level 3 | | Balance | | | | | | | | | | | | | | | | Financial Assets | | | | | | | | | | | | | | Cash equivalents | | $ | 11,972,733 | | $ | 141,869,024 | | $ | - | | $ | 153,841,757 | | Short-term investments | | | - | | | 66,810,962 | | | - | | | 66,810,962 | | Total financial assets measured at fair value | | $ | 11,972,733 | | $ | 208,679,986 | | $ | - | | $ | 220,652,719 | | | | | | | | | | | | | | | | Financial Liabilities | | | | | | | | | | | | | | Current portion of derivative instruments related to stock purchase warrants | | $ | - | | $ | - | | $ | 1,465,272 | | $ | 1,465,272 | | Total financial liabilities measured at fair value | | $ | - | | $ | - | | $ | 1,465,272 | | $ | 1,465,272 | |
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Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] |
The following table sets forth a summary of changes in the fair value of the Company’s Level 3 liabilities for the three months ended March 31, 2017 and 2016: | | | | | | | | Exercised | | | | | | | Balance as of | | Unrealized | | Stock Purchase | | Balance as of | | | | December 31, | | Losses | | Warrants | | March 31, | | Description | | 2016 | | 2017 | | 2017 | | 2017 | | Derivative liabilities related to stock purchase warrants | | $ | 1,465,272 | | $ | 90,191 | | $ | (1,555,463) | | $ | - | | | | | | | | | | Exercised | | | | | | | Balance as of | | Unrealized | | Stock Purchase | | Balance as of | | | | December 31, | | (Gains) | | Warrants | | March 31, | | Description | | 2015 | | 2016 | | 2016 | | 2016 | | Derivative liabilities related to stock purchase warrants | | $ | 508,202 | | $ | (39,898) | | $ | - | | $ | 468,304 | |
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