US options trading fell 9.3% in July, compared with the same month in 2009, to 277m contracts. Average daily volume reported by the Options Clearing Corp fell 5.0% to 13.2m contracts.After the market set a new record of 405.9m contracts in May, June was quieter, with 311.2m contracts cleared – 2% less than in June 2009 and 23% below May's tally. Now July's volume has turned out 11% lower than June's....