"One of the greatest risk to retirees' portfolios is inflation," Marie Dzanis, Head of Distribution for FlexShares and Northern Trust, told ETF Trends in a call. The Federal Reserve said that inflation grew slightly across most of the U.S. from April to mid-May as the improved employment situation has contributed to higher labor costs, Reuters reports. "Tight labor markets were widely noted in most districts," the Fed said, referring to the U.S. central bank's 12 regional branches.