When Deutsche Bank’s fund management arm raided rival Amvescap a few weeks ago and lured away 17 money managers, it highlighted a global shake-up occurring in the formerly cautious world of fixed-income money management.

Pension funds are under pressure to shift more money into bonds in order to more closely match their liabilities, but they are also trying to lift returns. These twin goals have helped fuel an explosion of new, more aggressive fixed-income strategies using leverage, short selling, and derivatives.