The ARTAX symbol is pretty old. I don't know how long "Artillium" has been quoted as ARTA on the LSE. AIM uses "codes" not "ticker symbols." http://www.londonstockexchange.com/exchange/prices-and-markets/stocks/summary/company-summary.html?fourWayKey=GB00B1L7NQ30GBGBXASQ1 10 pounds!