Shares of biotech firm Amarin (AMRN, quote) were crushed in after hours trading on Thursday after the company announced plans to raise $100 million in debt financing and to hire 250-300 sales reps to market its fish-oil drug Vascepa. The stock finished the after hours session down more than 18 percent at $9.75. Shares traded as low as $8.76 in the immediate aftermath of the announcement.