NO.PZ2020021204000041
问题如下：
An interest rate swap starts on June 1, 2019, and involves a six-month Libor being paid and a fixed rate of 5% being received every six months on a principal of USD 5 million. When does the first exchange take place?
How is it calculated?
解释：
The first exchange will take place six months after June 1, 2019, on December 1, 2019. It will be calculated as:
0.5 X (0.05 - R) x USO 5,000,000
where R is the Libor rate on June 1, 2019.
老师，请问为什么计算要实际利率减去libor呢
