How long does it take to refinance a loan?

On a clean file it should take no more than 15-20 business days to close a refinance.

How are interest rates determined?

This is a loaded question. Here's an interesting link below that helps explain it. Take a look at how closely the 10 year Treasury Bonds move with the Conventional Mortgage rates.

http://www.frbsf.org/education/activities/drecon/2002/0206.html

Is it a good time to lock?

Rate's have been low. Depending on your current rate, current loan terms and financial situation, now is certainly not a bad time to lock! If your not ready to lock though, be sure that your information is on file and ready for when your ready to lock! When it's time to lock your rate, we need to be ready!