How does the iPhone 6 fingerprint software work while asleep?

I have the finger security software enabled on my iPhone. When I fall alseep, am I vulnerable to a potential third-party being able to place my thumb on the designated security pad (i.e. Home button) whilst I'm sound alseep?

I live with some highly untrustworthy people, and I store valuable financial data on my phone. I'm somewhat concerned that one night, when I'm sleeping, they may attempt to gain access to my phone by using my thumb.

Your fingerprint doesn't change while you're sleeping so, of course, it would still work.

Find something realistic to obsess over.

Well yea it would work since it is still your fingerprint at the end of the day, whether you are sleeping or awake.

If anything make sure at least your phone is not able to be used/accessible during that time & you should be fine. Another option, though it would be inconvenient to you would be to disable Touch ID.