Why GW Pharmaceuticals, Louisiana-Pacific, and IAMGOLD Slumped Today

Friday marked a fitting end to a good week for the stock market, with the S&P 500 and Nasdaq Composite posting solid gains of around 0.25% to 0.5% to end a successful third quarter of 2017. Favorable sentiment following the release of the federal government's tax reform proposal and good domestic economic data supported the ongoing advance of major market benchmarks, and investors still seem generally optimistic about the prospects for stocks heading into the final three months of the year. Still, some companies had to deal with disappointing news that led to their shares losing ground. GW Pharmaceuticals (NASDAQ: GWPH), Louisiana-Pacific (NYSE: LPX), and IAMGOLD (NYSE: IAG) were among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

Shares of GW Pharmaceuticals finished lower by 11% in the wake of a successful clinical trial by one of the company's rivals. The cannabinoid treatment specialist has been looking to use its Epidiolex lead candidate drug to fight severe epilepsy syndromes such as Dravet syndrome, and investors have been optimistic about GW's prospects in the space. However, a small company called Zogenix said today that it had seen positive study results for its own Dravet syndrome treatment, including reduced seizure rates for patients. That could leave Epidiolex missing out on being the first available solution for treating Dravet syndrome, and investors weren't pleased with the potential for tougher competition than they had hoped.

Image source: GW Pharmaceuticals.

Source: Fool.com