Mortgage bonds are down to their worst level in months and crossed beneath the 200 Day Moving Average today which is not a good sign, remember as mortgage backed securities go down in price, rates get worse. They are currently trading just above the 200 DMA, this is very significant bc the last time it touched the 200 DMA was January 13th, over 10 months ago.  Rates have moved up slightly this AM and you could float if you are keeping your eyes peeled, but overall I would advise locking.