Warrants and Warrant Derivative Liability	12 Months Ended
Dec. 31, 2017
Warrant
Warrants and Warrant Derivative Liability	(7) Warrants and Warrant Derivative Liability On October 16, 2009, the Company completed a $70.0 million private placement with both existing and new investors resulting in $62.3 million in net proceeds and an additional $3.6 million from bridge notes converted in conjunction with the private placement. In consideration for the $62.3 million in net cash proceeds Amarin issued 66.4 million units, each unit consisting of (i) one ADS (representing one ordinary share) at a purchase price of $1.00 and (ii) a warrant with a five-year term to purchase 0.5 (one half) of an ADS at an exercise price of $1.50 per ADS. In consideration for the conversion of $3.6 million of convertible bridge notes, Amarin issued 4.0 million units, each unit consisting of (i) one ADS (representing one ordinary share) at a purchase price of $0.90 and (ii) a warrant with a five-year term to purchase 0.5 (one half) of an ADS at an exercise price of $1.50 per ADS. The total number of warrants issued in conjunction with the financing was 35.2 million. In conjunction with the October 2009 financing, the Company issued an additional 0.9 million warrants to three former officers. The warrants issued in connection with the October 2009 financing contained a pricing variability feature which provided for an increase to the exercise price if the exchange rate between the U.S. dollar and British pound adjusts such that the warrants could be exercised at a price less than the £0.5 par value of the common stock—that is, if the exchange rate exceeded U.S. $3.00 per £1.0 sterling. Due to the potential variable nature of the exercise price, the warrants were not considered to be indexed to the Company’s common stock. Accordingly, the warrants did not qualify for the exception to classify the warrants within equity and were classified as a derivative liability. The fair value of this warrant derivative liability was remeasured at each reporting period, with changes in fair value recognized in the consolidated statement of operations. Upon exercise, the fair value of the warrants exercised was remeasured and reclassified from warrant derivative liability to additional paid-in-capital. Although the warrants contained a pricing variability feature, the number of warrants issuable remained fixed. Therefore, the maximum number of common shares issuable as a result of the October 2009 private placement was 36.1 million. In October 2014, the Company and the holders of the remaining October 2009 warrants mutually agreed to extend the expiration date of such warrants from October 16, 2014 to February 27, 2015. Of the 8,087,388 warrants outstanding as of December 31, 2014, 1,844,585 warrants were exercised, resulting in net proceeds to the Company of $2.7 million, and the remaining 6,242,803 warrants expired. The related derivative liability was extinguished and we recognized a $0.1 million gain on change in fair value of derivative liability for the year ended December 31, 2015. No warrants were outstanding as of December 31, 2017 and 2016.

(7) Warrants and Warrant Derivative Liability

On October 16, 2009, the Company completed a $70.0 million private placement with both existing and new investors resulting in $62.3 million in net proceeds and an additional $3.6 million from bridge notes converted in conjunction with the private placement. In consideration for the $62.3 million in net cash proceeds Amarin issued 66.4 million units, each unit consisting of (i) one ADS (representing one ordinary share) at a purchase price of $1.00 and (ii) a warrant with a five-year term to purchase 0.5 (one half) of an ADS at an exercise price of $1.50 per ADS. In consideration for the conversion of $3.6 million of convertible bridge notes, Amarin issued 4.0 million units, each unit consisting of (i) one ADS (representing one ordinary share) at a purchase price of $0.90 and (ii) a warrant with a five-year term to purchase 0.5 (one half) of an ADS at an exercise price of $1.50 per ADS. The total number of warrants issued in conjunction with the financing was 35.2 million.

In conjunction with the October 2009 financing, the Company issued an additional 0.9 million warrants to three former officers. The warrants issued in connection with the October 2009 financing contained a pricing variability feature which provided for an increase to the exercise price if the exchange rate between the U.S. dollar and British pound adjusts such that the warrants could be exercised at a price less than the £0.5 par value of the common stock—that is, if the exchange rate exceeded U.S. $3.00 per £1.0 sterling. Due to the potential variable nature of the exercise price, the warrants were not considered to be indexed to the Company’s common stock. Accordingly, the warrants did not qualify for the exception to classify the warrants within equity and were classified as a derivative liability.

The fair value of this warrant derivative liability was remeasured at each reporting period, with changes in fair value recognized in the consolidated statement of operations. Upon exercise, the fair value of the warrants exercised was remeasured and reclassified from warrant derivative liability to additional paid-in-capital. Although the warrants contained a pricing variability feature, the number of warrants issuable remained fixed. Therefore, the maximum number of common shares issuable as a result of the October 2009 private placement was 36.1 million.

In October 2014, the Company and the holders of the remaining October 2009 warrants mutually agreed to extend the expiration date of such warrants from October 16, 2014 to February 27, 2015. Of the 8,087,388 warrants outstanding as of December 31, 2014, 1,844,585 warrants were exercised, resulting in net proceeds to the Company of $2.7 million, and the remaining 6,242,803 warrants expired. The related derivative liability was extinguished and we recognized a $0.1 million gain on change in fair value of derivative liability for the year ended December 31, 2015. No warrants were outstanding as of December 31, 2017 and 2016.