Quarterly report pursuant to Section 13 or 15(d)

Consolidated Statements of Cash Flows

Consolidated Statements of Cash Flows - USD ($)
6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Cash flows from operating activities    
Net income (loss) $ 2,920,109 $ (39,242,373)
Adjustments to reconcile net income (loss) to net cash used in operating activities:    
Depreciation 84,413 71,081
Stock-based compensation expense 693,701 853,814
Change in fair value of warrant liabilities (16,435,761) 25,077,142
Decrease in deferred rent   (13,526)
Net amortization of premium on marketable securities 121,592 315,673
Changes in operating assets and liabilities:    
Increase in prepaid expenses and other current and non-current assets (1,009,217) (315,653)
(Decrease) increase in accounts payable, accrued liabilities and other liabilities (2,489,141) 52,631
Net cash used in operating activities (16,114,304) (13,201,211)
Cash flows from investing activities    
Purchases of marketable securities   (11,129,302)
Proceeds from sales of marketable securities 15,191,125 21,978,888
Purchases of property and equipment (19,999) (79,276)
Net cash provided by investing activities 15,171,126 10,770,310
Cash flows from financing activities    
Proceeds from exercise of warrants   5,503
Net cash provided by financing activities   5,503
Net decrease in cash and cash equivalents (943,178) (2,425,398)
Cash and cash equivalents at beginning of period 8,320,317 6,995,046
Cash and cash equivalents at end of period 7,377,139 $ 4,569,648
Supplemental disclosures of cash flow information:    
Right-of-use assets obtained in exchange for lease obligations 4,148,672  
Leasehold improvement obtained in exchange for lease incentive obligations $ 189,227