Coca Cola (KO, news, chart, volatility) puts are seeing active trading Thursday. Volume is running three times the usual, with 28,000 puts and 5,800 calls traded. The October 52.5 puts are the most actives, with 13,300 traded, 52 percent trading on the offer and 27 percent midmarket. Open interest in that contract is 2,300. The January 50 and 55 puts are also busy, with more than 80 percent trading on the offer. Shares are holding up relatively well, down just 16 cents to $54.00, but the action is the options market seems to suggest some investors are worried KO might falter in the next two weeks or perhaps some time in the fourth quarter. No news on the stock today. Earnings due out mid October, perhaps before the options expiration.