After serving the market for almost 20 years, the trading floor in Exchange Square is to undergo its first overall renovation. Today will be the hall's last day of trading in its present guise, and the work, starting on Saturday, will last until April next year. Once completed, the hall will be a fraction of its original size, with 300 trading booths instead of 900. It will house a visitor's gallery, a media booth, seminar rooms and a museum. The growth of electronic markets has seen 95 per cent of trading activity move off-site. Trade will continue during the renovation.