UUP goes long the US dollar and shorts the currencies of major US trading partners using USDX futures. Specifically, the fund is shorting the euro, Japanese yen, British pound, Canadian dollar, Swedish krona and Swiss franc. The USDX's currency weights have been fixed since 1973: It departs from its benchmark by being heavily exposed to the euro, so positive moves in the euro will have strong, negative impacts on the fund. Structured as a commodities pool, UUP distributes K-1s and is marked-to-market at year-end.