Sandridge Energy (SD) is down 31 cents to $12.08 after Goldman Sachs downgraded the stock to Sell from Neutral. More than 5,000 Dec 16 calls traded, 99 percent hitting ask-side. Another 1,279 Dec 12.5 calls traded, with 55 percent hitting ask-side. Looks like early call buying in the Oklahoma City oil and gas company, but might be closing, as volume does not yet exceed open interest.