During the year ended December 31, 2017 and in connection with the Private Placement, investors received warrants to purchase 5,929,256 shares of common stock. The warrants have an exercise price of $2.41 per share and expire three years from the date of issuance. The placement agent also received 237,170 warrants to purchase shares of common stock as part of its placement agent fee. The placement agent warrant has an exercise price of $2.89 per share and has a three-year term from the date of issuance. The warrants contain a provision to protect investors from potential future dilutive events, or a down-round provision. The Company elected to early adopt ASU 2017-11 and will recognize the value of the effect of the down-round provision, if and/or when triggered.

 

The warrants were sold with shares of common stock for $2.535 per unit. The unit price was allocated to the warrants and common stock based upon the pro rata fair market value of the securities, with the warrants valued using the Black-Scholes model. The allocated fair value of the warrants was estimated to be $4.7 million on the date of issuance. In addition, the placement agent warrant was valued at $249,440 on the date of issuance.

 

The assumptions used in the Black-Scholes model for these warrants are as follows:

  

 

A summary of the Company’s warrant activity and related information is as follows:

  

 

No warrants were unvested at December 31, 2018. For the Company’s two largest beneficial owners, the warrants they received in connection with the Private Placement may be exercised only to the extent that the total number of shares of common stock then beneficially owned by these shareholders does not exceed 9.99% of the outstanding shares of the Company’s stock. The weighted average remaining life is 1.1 years. The estimated aggregate pretax intrinsic value (the difference between the Company’s stock price on the last day of the year ended December 31, 2018 and the exercise prices, multiplied by the number of in-the-money warrants) is $0.