Weatherford (WFT, news, chart, volatility) call options are actively traded Friday morning. Shares are down 28 cents to $12.51 after crude oil slipped $2.90 to $51.54 a barrel. In the options market, most of the activity is in the December 17.5 calls, with 3,500 contracts traded. The top trade of the day is 400 contracts traded offerside for 22 cents. Most of the day’s other volume has been in fewer than 300 contracts for 20 cents. Implied volatility is up 19 points to 111 percent.