Winners and Losers as of 10:55AM

Winners: Walter Energy WLT is trading up roughly 6.90% near $118.5 after Citigroup initiated coverage with a Buy rating.
First Majestic Silver AG is trading up roughly 5% near $23.70 as the price of silver has risen over 2%.
Greenhill & Co GHL is trading up over 4.70% near $48.70 after the company's profits beat estimates.
ImmunoGen IMGN is trading up roughly 4% near $16.
Extorre Gold Mines XG is trading up almost 4% near $13 as the price of gold rose to $1600.

Losers: WebMD WBMD is trading almost 30% lower near $32 after the company cut its guidance.
MGIC Investment MTG is trading roughly 19% lower near $4.90 after the company reported a second quarter loss.
SkyWest SKYW is trading roughly 15% lower near $12.50 after the company was cut to Market Perform at Raymond James.
Entropic Communications ENTR is trading roughly 13% lower near $7.35 after the company was cut to Sell at Stifel Nicolaus.
Endeavour International END is trading roughly 10% lower near $14.80 after the company entered into an agreement to divest its Marcellus Shale asset.