Best way to scroll long content on mobile screen?

I am trying to decide the best way to have a certain amount of content scroll on a mobile screen.

Background: I am developing a mobile app for keeping track of your bills and expenses. I am trying to create a screen that shows all of the charges the user has made on a credit card during the current billing cycle.

Dilemma: For some users this list will be small and can easily be shown on the visible portion of the screen, while for others they will have to scroll to see everything.

My Question: I am trying to decide between two basic options. One has the content in a scrollable window, which keeps the CLOSE button on the screen. The other throws all the content into the main screen and you have to scroll down to access the CLOSE button.

Which one is better? And why?