|6 Months Ended|
Jun. 30, 2016
We have issued certain warrants which contain an exercise price adjustment feature in the event we issue additional equity instruments at a price lower than the exercise price of the warrant. The warrants are described herein as derivative warrants. As of June 30, 2016 all derivative warrants have either expired or have been exercised.
On May 25, 2016, we issued 1,357,301 warrants to purchase shares of our common stock as part of our 2016 Offering. Subject to certain ownership limitations, the warrants will be initially exercisable commencing six months from the issuance date at an exercise price equal to $2.25 per share of common stock. The warrants are exercisable for five years from the initial exercise date.
The following table summarizes the warrant activity for the six months ended June 30, 2016 (in thousands, except exercise price):