Calls in Schering Plough (SGP, news, chart, volatility) are seeing a burst of trading this afternoon, with shares more than 5% higher, near $15.26, and multiple sweep buyers in upside 20 strike calls in Nov, Dec, and Jan expiries. Nearly 15,000 Nov 20 calls have traded in the past 20 minutes, priced at 10cents and possibly initiated to close a short call position at the strike, where open interest stands near 42,000 contracts.