My bowtech has not moved since the day I got it and it is two years old. How do I know this, I marked the cam so I would know when it stretched. And so far nothing. I am even missing a few strands and it is still in the same place. It does need replaced though.
If they do stretch it is not enough that you can notice or that it would effect tuning or timing.
Paul
I have to say from my experiences this would be the exception not the norm.
I have never owned a bow that I did not have
any string stretch or creep occur on, let aloneafter two years.
Must be why there are so many custom string companies....... To replace all of the no stretch, nocreep factory strings.