Global debt at negative yields plummeted below $3 trillion for the first time since December 2015, according to an analysis by Deutsche Bank. With more central banks tightening monetary policy and unveiling efforts to raise interest rates to combat inflation, the share of subzero debt as a percentage of total outstanding bonds cratered in the last week. A research note from the financial institution, first reported by MarketWatch, highlighted that government-issued negative-yielding bonds fell to 8 percent of the total market, down from a peak of 40 percent in September 2019. Corporate negative-yielding bonds plunged to 0.1 percent, down from the record high of about 10 percent at the end of 2021, the bank said. The last time shares of negative-yielding government and corporate debt were this low was in February 2015 and February 2020, respectively. Negative-yielding bonds give investors a guaranteed loss if they are held to maturity. But …