The Invesco Optimum Yield Diversified Commodity Strategy No K1 ETF (PDBC) and the Energy Select Sector SPDR ETF (XLE) are among its holdings. Invesco Optimum Yield Diversified Commodity Stratgy No K1 ETF (PDBC): ETF Research Reports Before the war in Ukraine started, many experts predicted that inflation would cool off in spring as supply chains improve after pandemic driven disruptions.