Macquarie Bank yesterday finalised the sale of $500 million for the PUMA Masterfund P-13 trust, one backed by unusually prime, full documentation mortgages. Macquarie upsized the issue from a planned size of $300 million foreshadowed to investors earlier in the week. After testing the market for pricing a spread over the one month bank bill swap rate in the high 30s, Macquarie agreed on a spread of 40 basis points over the one month swap rate on the senior, AAA-rated tranche of $485 million. The bank sold the subordinated tranche of $15 million in Puma bonds at a spread of 82 basis points over swap.The mortgage collateral is highly seasoned (at 20 months) and well secured, with a weighted average loan to valuation ratio of 67 per cent.According to a bank media release, "interest came from a broad number of Australian and Asian accounts" putting to bed market chatter the joint leads - Deutsche Bank and Societe Generale, in addition to Macquarie - were going to hold the paper themselves.If there's any controversy over the Macquarie RMBS deal it's the pricing, which is somewhat lower than the apparent price of Puma bonds in the secondary market,  although actual levels are contested given the state of the market.There's plenty of other noise in the undergrowth of the mortgage-backed market as every issuer dependent on this market sniffs for investor appetite for, and likely pricing of, a bond issue.Investors say the issue remains more than mere price tension over the spread that has to be paid, with investors wary of buying mortgage-backed securities when there are few pricing references in the market. Issuers, meanwhile, are sensitive over disclosure of the spread they might end up having to pay, given the implications for repricing of their mortgage book. As a result there's plenty of interest in private placements, though no evidence that any have been completed.Among early movers may be Rams Home Loans, which is said to be in the preliminary stages of marketing an issue targeted at European investors. This is said to be for US$500 million, though there's no sniff of pricing or the composition of the portfolio. nabCapital and RBS Capital Markets are the leads for the putative issue. ABN Amro may also be working on a separate mandate from Rams. These three investment banks are also the swap providers under the terms of the extendible commercial paper programs on which Rams last month invoked its right to defer repayment of notional 30 day paper by six months.More than a third of Rams' loan book is currently funded in the XCP market in the US and must be refinanced through loan term bond issues or bank debt.