Today’s midday gainers are Molycorp Inc (NYSE:MCP), Sprint Corporation (NYSE:S), Alpha Natural Resources, Inc. (NYSE:ANR) and midday losers are Idenix Pharmaceuticals Inc (NASDADQ:IDIX), RetailMeNot Inc (NASDAQ:SALE), Textura Corp (NYSE:TXTR).

Idenix Pharmaceuticals

Molycorp is today’s top performing stock

Topping off our midday gainer list is Molycorp Inc (NYSE:MCP), the material stock shot up +13.31% to $5.45. Over last quarter, billionaire George Soros picked up 2.2 million shares, having paid $6.81 per asset. This position represents 0.16% of the billionaire fund.

Following Molycorp Inc. is Sprint Corporation (NYSE:S), the tech stock rose +8.38% to $10.80. As of September, billionaire Leon Cooperman holds 35.2 million shares, composing 3.32% of his fund. Another investor with a position in S is John Paulson, who owns 56.6 million shares, representing 2.27% of his holdings.

Last but not least is Alpha Natural Resources, Inc. (NYSE:ANR), the energy company increased +4.45% to $7.07. This was another hit for Paulson, since he owns four million shares, which represent 0.15% of his portfolio, acquired for $8.10.

Seth Klarman loses again with Idenix Pharmaceuticals

On the top of our midday loser list is Idenix Pharmaceuticals Inc (NASDADQ:IDIX), the biopharmaceutical company dipped -5.92% to $6.52. This was a blow for Seth Klarman who holds 39.8 million shares (4.40% of his fund), purchased for average $5.41.

The second stock in our list is RetailMeNot Inc (NASDAQ:SALE), the digital coupon marketplace dropped -5.40% to $28.85. Billionaire George Soros bought 200,000 shares (0.08% of his fund), at average $33.01 during last quarter.

Third and last stock is Textura Corp (NYSE:TXTR), the tech firm was down -5.27%, hitting $29.65. Over last quarter, George Soros bought 26,000 shares at $34.80, composing 0.01% of his fund.