问题如下：
A US bond portfolio manager wants to hedge a long position in a 10- year Treasury bond against a potential rise in domestic interest rates. He would most likely:
选项：
A.sell fixed- income (bond) futures.
enter a receive- fixed 10- year interest rate swap.
sell a strip of 90- day Eurodollar futures contracts.
解释：
A is correct.
The portfolio manager would most likely use a longer-dated fixed- income (bond) futures contract to hedge his interest rate risk exposure. The choice of the hedging instrument, in fact, will depend on the maturity of the bond being hedged. Interest rate futures, like 90-day Eurodollar futures, have a limited number of maturities and can be used to hedge short-term bonds. The mark-to- market value of a receive- fixed 10- year interest rate swap will become negative if interest rates rises, and thus the swap cannot be used as a hedge in this case.
逻辑上：想要against a potential rise，就是担心利率上涨，可以看作是支付利率的一方，不想支付更多的int，所以用swap应该是一个pay fixed的swap
题意上：long bond，不就是buy bond，持有bond 不就是收interest 吗？
这里为什么看似矛盾，考试时候如何判断正确收支interest方向。谢谢
