问题如下：
A bond portfolio manager wants to reduce the duration from 5.5 to 4.5 by interest rate swap, she would enter into a:
选项：
A.receiver swap involving paying fixed-rate payments and receiving floating-rate payments.
B.receiver swap involving paying floating-rate payments and receiving fixed-rate payments.
C.payer swap involving paying fixed-rate payments and receiving floating-rate payments.
解释：
C is correct.
考点：interest rate swap
解析：
投资者希望降低组合的duration，因此应该进入一个duration为负的interest rate swap。
因为固定端的duration大于浮动端的duration，所以付固定、收浮动的duration为负，即应该进入payer swap.
为什么付固定、收浮动的duration为负？付固定是固定利率还是固定margin加上一个基准的浮动利率？谢谢
