Should I lock the current mortgage rate for 6 months and bet?

[Jack Jiang]

My mortgage broker was offering to lock the current rate (investment, 6.4%, no point) for 6 months, at the cost of 0.5% of the mortgage amount. I am thinking about whether I should take that bet or not - say I pay 2k to lock 400k of mortgage, and wait until the end of the year to buy the dip. 

Hi fellow BPers, Would this be a good idea or a terrible one? Seems to me that the interest rate is just gonna go up and up, and the market is cooling down visibly now.