Bond king Jeff Gundlach hates just about everything these days. The elite investor thinks the spike in oil prices is unsustainable, U.S. stocks have little room left to rise and junk bonds will get trashed by a wave of energy defaults. But the billionaire founder and CEO of DoubleLine Capital saves his darkest warning for fans of negative interest rates. “Negative rates are really bad,” Gundlach cautioned during a webcast ...