Au

From BoardGameGeek:

Au is a real-time trading game for 4 players in which currency is backed by gold. The game takes about 45 minutes. Played over 4 rounds, players take the role of a nation and start the game with some of their own national currency and an equal amount in gold. (No debt, no credit). A round starts with players acquiring resources and printing currency. Then there is a timed trading session, after which resources can be spent to mine for gold. At the end of the game, players are awarded Victory Points for the currencies they hold, however, the victory points are ranked according to the currencies strength. -description from the designer