Several key mortgage rates trended upward today. The average rates on 30-year fixed and 15-year fixed mortgages both increased. Meanwhile, the average rate on 5/1 adjustable-rate mortgages also floated higher. Rates for mortgages are in a constant state of flux, but they have remained in a historically low range for quite some time. If you’re in the market for a mortgage, it may make sense to go ahead and lock if you see a rate you like. Just don’t do so without shopping around first.