Convertible bonds issued in the Chinese mainland gained the most in more than seven years last week and the co-manager of a fund that returned 57 percent in 2014 said he remained bullish, even after the nation's world-beating equity rally.

The S&P China Convertible Bond Index jumped 8.5 percent in five days, as a similar corporate debt benchmark was little changed.

The index is up 15 percent since the People's Bank of China cut interest rates for the first time in two years on Nov 21. This year's best-performing bond funds in China are focused on exchangeable debt.