So why are rates moving higher? It is complicated, as there are many factors, but the simplest explanation is that the economy is slowly getting better.
Another big reason is that the FED has been propping up mortgages by being the primary buyer of mortgage backed securities. Without them buying these securities, the entire mortgage system would collapse. While they have, and continue to say they will buy the securities for the immediate future, there are signs that this policy may be changing, with a pull back of the buying because of the improving economy
Simply put, rates may be slowly starting to return to where the market should be if supporting itself, and not being propped up by the Fed.