The average rate on a 30-year new purchase mortgage climbed for a third day on Thursday. Adding another 11 basis points, the flagship average is now up to 7.59%, which is its highest mark since July 10. The 30-year average swung dramatically last month, with rates spiking to a 20-year high of 7.70% on July 6, but then sinking to 7.17% one week later.
The 15-year mortgage…