CNBC.com's John Carney heard on good authority that fixed income desks are going to be subject to severe layoffs. His source had these comments, while dining in Manhattan's Grand Central Oyster Bar (which isn't cheap, for what it is).

"It's going to be a blood bath. Volume is down for everything except Treasuries and Munis. These guys aren't making money and soon they'll be out of their jobs."

"It's a one-two blow for fixed income.  The derivatives are being commoditized and put on exchanges.  Swoosh.  Now you don't need half the people you employ to trade and track those.  And volume on corporates and agency paper is way down."

Year to date, average daily trading volume in U.S. corporates is down 2% versus last year, according to SIFMA numbers.  Trading in Fannie Mae and Freddie Mac debt is down 7%.  Trading in MBS's sponsored by Fannie and Freddie is down 13%.  While the numbers have been trending down all year, trading really thinned out over the summer. 

"We're easily going to cut a quarter to a half of our traders and back office in fixed income. Everyone else is going to do it too," he says. 

Thanks, John.   [CNBC.com, 9/27]