Freddie Mac announced last week that Arch Reinsurance will provide credit-loss insurance to the GSE on a pool of mortgages used in the company’s first non-agency risk-sharing transaction. The $22.58 billion pool was used to create tranches sold to investors as part of Freddie’s first Structured Agency Credit Risk transaction. Arch will cover up to $77.4 million in losses on certain tranches of the deal. The STACR deal was structured so that Freddie will take the first 30 basis points of losses on the transaction, followed by private investors, which bought debt notes on the following 300 basis points of potential losses.