7.   Warrant Liabilities

On March 3, 2020, we amended certain outstanding warrants to purchase an aggregate of 11,552,314 shares of common stock, including the January 2020 Warrants and warrants we issued in connection with a financing in August 2019 (the “August 2019 Warrants”), to modify certain provisions that had required them to be previously classified as liabilities and to enable them to now be classified as equity under the relevant accounting standards. As a result, during the three months ended March 31, 2020, we reclassified the fair value of the warrants on the date of the amendment from warrant liabilities to additional paid-in capital in the condensed balance sheet and recognized a non-cash loss on changes in the fair value of warrants in the condensed statement of operations and comprehensive loss.

The following table provides a roll forward of the fair value of our warrant liabilities, the fair value of which was determined by Level 3 inputs for the six months ended June 30, 2020 (in thousands):

 

The warrant liability associated with the January 2020 Warrants was classified within Level 3 of the fair value hierarchy. The following table presents the weighted-average key assumptions used to calculate the fair value of the January 2020 Warrants:

 

 

The warrant liability associated with the August 2019 Warrants was classified within Level 3 of the fair value hierarchy. The following table presents the weighted-average key assumptions used to calculate the fair value of the August 2019 Warrants: