It will change depending on certain classes or by using an item. Shoes of the Wind? I think.Hence why I asked about it. This is my first Fire Emblem game, so I didn't know how stats work in the game/series. Plus, someone in previous page mentioned something about making HP 199 to 200 to keep 99 stats permanent, so yeah, was better to ask first while already having made 2 backups of my save.
So far I been playing with Byleth having 255 movement for the past 3 days and I'm in chapter 18. Haven't gotten a single crash at all.
Thanks for the links. but now I have another question.
How do you raise the Movement stat in the game itself?