The last time I was made to change my Chase password, I made it maximal length at the time (32 characters). However, it turned out their login page had an off-by-one error in the login page Javascript, such that it wouldn't let you type 32 characters in the field. I worked around it via using the browser debugging tools to fix the bug, then decided on a 30-character password as an additional margin of safety. They said they'd look into it, never heard back about it.