The negative effect is reinforced by the fact that, because CDS contracts are tradable, they tend to be priced as warrants, which can be sold at any time, rather than as options, which would require an actual default to be cashed in. People buy CDS contracts not because they expect a default, but because they expect the CDS to appreciate in response to adverse developments.
更为糟糕的是，CDS合同是可以交易的，作为一种保证书，它们可以标上价格，随时可以出售。而期权只能是在实际违约发生时才能变现。购买CDS合同的人并不指望违约的发生，而是希望市场在反向逆转的时候，靠CDS合同的升值赚钱。