Waiting several years to unify Fannie Mae and Freddie Mac securities into a single MBS could pose a huge risk to its successful completion, warned the mortgage banking industry, but Wall Street thinks it’s worth the wait to get market participants totally behind the move. The Federal Housing Finance Agency’s proposed single security for the government-sponsored enterprises met with conflicting views as the comment period ended this week. The proposal is aimed at eliminating Freddie’s pricing disadvantage and improving liquidity in the to-be-announced market. The Securities Industry and Financial Markets Association urged...