The global currency is a setting to allow the major size metrics to be comparable between StockReports. You can change this from the site settings panel and select either GBP, USD or Euros. This will determine for example the market cap currency in the top header of a stock report.
To get there, try the link to 'Site Settings' from the 'You' dropdown menu - on the top right of site. This will give you the options listed in the screenshot below: