The First Trust Low Duration Opportunities ETF is an actively managed exchange-traded fund that holds more than 1,000 mortgage-related securities. Its low duration model means it invests in mortgage securities with shorter maturity dates — its weighted average effective net duration is 2.49 years — which somewhat shields these securities from interest rate risk. The ETF has returned around 7% year over year on a total return basis as of Feb. 26, underperforming the S&P 500’s 18% gain over the same time peri ...