Mortgage rate locks and trends

[Martin T.]

I am in the process of purchasing my 2nd rental property, and have spoken with a number of banks regarding rates.  Since it's an investment property the rates have ranged from 4.25% to 4.75% (Monday they were 4.25% with one lender, but the lowest now is 4.5%).  How much have others seen the rates fluctuate, and am I doing the right thing by checking rates daily with the lenders before locking in?  Again, if I had locked in on Monday, the rate would have been 4.25 versus 4.5% today.  I'm also being encouraged by my agent and attorney to lock the rate soon to make sure everything can be processed before the closing (I'm currently 33 days away from closing, on 6/12).  A 45 day lock is more expensive than a 30 day lock since banks can better predict what actual rates might be at closing from what I've been told.

Any advice would be greatly appreciated!