The graph on the portfolio page below represents the value of your portfolio against the market value. This is a sum of the value of the individual items in your portfolio. For bottles in cask (virtual bottles), the market value is based on the last transaction price, or if no transactions have yet taken place, the purchase value of the virtual bottle. For physical bottles, the market price is based on THE SWEX market price. THE SWEX market price is built using historical data from four components: Whiskystats auction data, Whiskystats retail sales data, THE SWEX transactions, and SWI investment management agreement transactions. This line builds up the amount to the present day and allows you to track your initial investment.