A growing number of 40-year mortgages are being securitized – evidence that the product has taken hold in the origination market. On one level, it’s not surprising that 40-year mortgages have become popular. The extended amortization product is often pitched as a way for borrowers to increase their buying power by spreading their payments out over a longer time span. Although some analysts have suggested that the savings aren’t that great, and that they drop precipitously past the 40-year mark, lenders have clearly done...