Rates are based on bonds and bonds have been taking cues from oil prices this week. Oil was flat overnight, bringing bonds along for the sideways ride. As such, the average mortgage lender began the day almost perfectly in line with yesterday's latest levels. 

All that having been said, bonds experienced some of their own weakness in the afternoon, independent from oil prices (which continued sideways to slightly lower). Some mortgage lenders may choose to raise rates a bit before the end of businesses.  Those who don't will instead have to adjust for this market movement on Monday morning (assuming bonds don't change much by then).