Global credit markets are running at their hottest in two decades, prompting some of the world’s biggest money managers, including Aberdeen Investments and Pimco, to warn against complacency about the risks.Yield premiums on corporate debt have fallen to just over one percentage point, the least since June 2007, amid confidence about the economic outlook, a Bloomberg index of bonds across currencies and ratings shows.That all presents a paradox. Money managers don’t want to miss out on the rally. But the ru ...