Dive summary:

• The fixed annual rate for a 30-year mortgage got down to 3.36% in the weekly survey of rates conducted by Freddie Mac and released Thursday.
• That made last week's 3.4% rate a record low for only seven days and made last year's corresponding rate – 3.94% – seem much higher than it did then.
• A 15-year, fixed-rate loan was at 2.69%, also a new record low.

From the article:

A weakening economy and the Federal Reserve’s continued purchase of mortgage securities took the 30-year, fixed-rate mortgage to historic lows for the second straight week. ...