Bonds of all types worldwide are generating their biggest losses since 2010 this month, raising concern that the four-year bull market that pushed interest rates to record lows may be ending as the flood of easy money from the U.S. Federal Reserve subsides.

"For a very long time, the market dynamics in interest rates have been overwhelmed by Fed monetary policy," said Jeffrey Rosenberg, chief investment strategist for fixed-income at New York-based BlackRock Inc., the world's biggest money manager, which oversees $3.5 trillion. "Has the big inflection point been reached?"

From the debt of U.S. government and Latin American phone companies, from Japanese prefectures to Shariah-compliant borrowers, fixed-income securities have lost 0.65 percent on average in March, their worst performance since tumbling 1.09 percent in November 2010, according to the Bank of America Global Broad Market Index that tracks about $40 trillion of bonds. The drop has been led by U.S. Treasuries, which are down 1.5 percent, including a 5.9 percent plunge in the benchmark 30-year bond.