(Bloomberg) -- Investors who stuck with bonds from countries that defaulted or are on the brink are betting the double-digit returns they’ve posted over the past month are just the start of a rally.Most Read from BloombergPowell Haunted by Repo Crisis as Fed Aims to Cut Balance SheetMove Over Dubai. This Tiny Emirate Wants to Be the Next Haven for BillionairesJack Ma’s Clash With Beijing Costs Ant, Alibaba $850 BillionYellen Says US-China Ties on ‘Surer Footing’ After Beijing VisitChina Slides t