The ETRACS UBS Bloomberg Constant Maturity Commodity Index Total Return ETN Series B are senior unsecured debt securities issued by UBS that provide exposure to potential price appreciation in the UBS Bloomberg Constant Maturity Commodity Index Total Return. The index is designed to be a diversified benchmark for commodities as an asset class. It is comprised of futures contracts on 27 components, representing 24 commodities, with up to five different maturities for each individual commodity. The overall return on the index is generated by two components: uncollateralized returns on the futures contracts comprising the index and a daily fixed-income return.