The only time when it is advantageous to lock the rate is if there is danger of it rising and at the current time, that is not expected to happen for a while.
Rates are always changing. I remember when my credit union was oppering 12% on CDs.
In specifics regarding your stetment, you didn’t say what the loan was for and that matters a lot. Car loans from banks and credit unions is usually much higher than if the loan is for a home.
Often times, car manufacturers may be offering zero percent loans just to move inventory. Home builders with ‘their own’ mortgage companies often use lower interest rates to also move inventory.
My builder’s mortgage company immediately sells the notes to other investors and doesn’t service them at all.
They take an immediate profit from selling to other investors at slightly higher than the current going rate while the investors hope that the borrowers keep the current loan and not refinance elsewhere.
I know that by immediately refinancing, I can get a lower rate elsewhere. I already have formal approval letters from three other mortgage companies for rates that are lower than my inital rate from the builder
I just asked for and received yesterday a ‘good faith estimate’ from my lender and thay have already dropped their rate by over 1/2% since I initally applied a couple of months ago.
The bottom line is that one still needs to shop around to get the best deal and in my case, that ment taking the builders incentives and then refinancing as soon as possible elsewhere.