Mortgage rates were at their best levels in roughly a month last Friday afternoon. Since then, they've risen modestly on each of the past two business days. As has been the case for quite some time, day-to-day movement continues to be very tame. The actual interest rates at the top of loan quotes rarely change from one day to the next. Instead, fine-tuning adjustments to the overall cost of financing come courtesy of slightly higher upfront costs--at least in today's case.
In other words, if you were being quoted 3.875% yesterday on a 30yr loan yesterday, chances are you'd be seeing the same rate today, but with upfront costs just a bit higher (or a lender credit that's just a bit lower, depending on the scenario).
In the bigger picture, rates are attempting to push lower after rising fairly quickly from early September through early October. The weakness (read: slightly higher costs) over the past 2 days doesn't derail that effort, but that could change if the weakness persists for another day or two.