HANG Seng Index futures contracts traded at a discount to the cash market for most of the day as rollover activity continued to dominate trading. Turnover was heavy, with a total of 23,485 contracts traded worth $11.3 billion. Volume in September contracts was 12,859 while October contract volume was 10,626. With expiry due on September 29 and the possibility of a rate increase, many investors were covering their short positions in the market, said Jardine Fleming Futures head of derivatives research Virginia Mumford. 'It was a very quiet day but there was a lot of spread trading and rollover activity. 'Traders were repositioning themselves in the options market, buying back short positions,' she said. Total options volume was 3,373 contracts, representing 14.36 per cent of futures volume, and carrying open interest of 55,330 lots. Jardine Fleming said: 'The market continued to trade in a narrow range ahead of the Fed meeting. 'Overseas players sold down the futures to the 9,590 mark before finding any support.' Strong local selling in the afternoon continued as local sellers joined in to push the September futures straight down to 9,553, but there was some buying late in the afternoon.