The flow of jumbo mortgages channeled into the MBS markets began to slow in the third quarter of this year, according to a new market analysis and ranking by Inside MBS & ABS. After peaking at $72.3 billion in new issuance during the second quarter, the volume of newly securitized mortgages that exceed Fannie/Freddie loan limits dropped to $69.4 billion, a decline of 4 percent.