Mortgage rates rose yesterday after a better than expected advance read on third quarter GDP sent benchmark yields higher early in the trading session. Making matters worse for the fixed income sector was a recovery rally in stocks and a 1pm Treasury auction. As explained in previous posts, added supply of Treasury debt can have negative effects on yields as traders look for any reason to force rates higher in an effort to earn greater returns. Its the old econ 101 principle: if supply is greater than demand, then prices must fall enough to entice demand. Well...when Treasury prices fall, yields rise, and so do mortgage rates. Yesterday the deck was stacked against the rates market...better than expected econ data, a Treasury auction, and rallying stocks! That's why mortgage rates moved higher.......