State Street Global Advisors (SSgA), the Boston-based third largest US issuer of exchange-traded funds, and DoubleLine Capital – promoted by star fixed-income manager Jeffrey Gundlach, recently rolled out a pair of new ETFs; one aimed at fixed income securities from emerging markets and another at short-maturity bonds. The actively managed SPDR DoubleLine Emerging Markets Fixed Income ETF (EMTL) seeks to …