Mortgage interest rates -- just like stock prices -- change price daily and you can win big or lose big if you don't know what you are doing.

Everyday Loan Officers are ask "what do you think interest rates are going to do?" Of course none of us know that answer, so except for the most extreme cases on a purchase transaction, I suggest you always lock, and to do it as soon as you can. The sooner you lock your rate, the less chance you have of losing in the mortgage interest rate game

If you have a signed purchase contract in hand, lock your rate as soon as possible. There is no better way to protect yourself from the fickle mortgage markets. Holding out for 1/8th - 1/4% more is just not worth the risk! If you want to gamble... go to Vegas.

With interest rates currently hovering near historic lows, the chance of any meaningful rate drop is low. The chance of rates going higher is very big.

It is better to win and lock on a known great rate, and be slightly annoyed if interest rates go down a little before closing, than to be floating and lose with rates dramatically higher before closing.

One other aspect... You have so many other things to do during the buying process than to keep stressing yourself out by looking at mortgage interest rates all day. Just lock and be done!

A refinance transaction on the other hand is different. The new refinance rate has to make sense to act. According to a recent survey, most people refinance when the difference between their current rate and any new rate is at least 1% or greater. You can potentially gamble a bit more because you are not under any time restraints, but if today's refinance rate is close, take it and run.

Finally, we always suggest monitoring one of the interest rate advisory sites for good daily interest rate float or lock advice.