Commonwealth Bank tapped into the resurgent mortgage-backed securities market, with a deal that was upsized from A$750 million to $2.3 billion. On Friday, the bank priced its latest RMBS issue, Medallion Trust Series 2013-1. It will pay 80 basis  over the bank bill swap rate on the $1 billion of A1 notes, which have a weighted average life of 2.3 years.This is better pricing than Westpac achieved a week earlier, when it priced the senior tranche of Series 2013-1 WST Trust at 85 bps over the swap rate. The $1.9 billion tranche has a longer life than the A1 tranche of the Medallion Trust, however - three years compared with 2.3 years.Commonwealth Bank priced the $1 billion of A2 notes, which have a weighted average life of 3.5 years, at 88 bps over the swap rate. CBA included a soft bullet tranche in the issue. The $250 million of A3 notes have a maturity date of February 2018. They carry a fixed coupon of 4.25 per cent, which equates to 80 bps over swap.The CBA issue comes on top of Westpac's $2.1 billion issue and Bendigo and Adelaide Bank's $850 million issue, Torrens Series 2013-1.Bloomberg reported that ING Bank (Australia) had put plans in place to issue up to $2 billion of RMBS this year.