问题如下：
To close the position on the hypothetical Orion trade, the fund:
选项：
A.sells protection at a higher premium than it paid at the start of the trade.
B.buys protection at a lower premium than it received at the start of the trade.
C.buys protection at a higher premium than it received at the start of the trade.
解释：
B is correct.
The trade assumes that £6 million of five-year CDS protection on Orion is initially sold, so the fund received the premium. Because the credit spread of the Orion CDS narrowed from 150 bps to 100 bps, the CDS position will realize a financial gain. This financial gain is equal to the difference between the upfront premium received on the original CDS position and the upfront premium to be paid on a new, offsetting CDS position. To close the position and monetize this gain, the fund should unwind the position with a new offsetting CDS, thereby buying protection for a lower premium (relative to the original premium collected) in six months.
这道题，最开始short CDS在利差缩窄以后是赚钱还是亏钱？我看有助教的解答“”“所以之前的头寸，已经实现了盈利，因为之前卖出CDS protection时，收到的保费是按照更高的Credit spread定价的，而现在的Credit spread降低。”，但是卖CDS不是long credit risk吗？credit risk下降应该是亏钱啊，
