English to Chinese Bus/Financial Insurance

How did XXX get into financial distress? Non-insurance entities are not subject to the strict solvency framework applied to insurers. This allowed various non-insurers to engage in risky credit transactions (huge positions in credit derivative swaps on mortgage-backed securities) without the appropriate limits and minimum capital/surplus to protect the company from a downswing in the mortgage-backed security markets.

(huge positions in credit derivative swaps on mortgage-backed securities)：拿不准这句中...in...on...的逻辑关系（按揭证券在信用衍生交换中涉及巨额头寸？） 。希望得到大家的指点。