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Stock Incentive Plan (Tables)
9 Months Ended
Sep. 30, 2019
Stock Incentive Plan  
Schedule of weighted-average assumptions for options granted

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Nine months ended September 30,

    

2019

​

2018

    

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Expected term (in years)

 

5.76

​

6.22

​

Expected volatility

 

56.03

%  

49.73

%  

Risk free rate

 

1.54

%  

2.69

%  

Expected dividends

 

—

%  

—

%