It is possible to do so. Go to your profile.
Then from side menu:
Go to 'Look and Layout Preference'.
Then you will see this option: 'Show most recent posts at the top'
Check the box and click 'Change Profile'.
But I really hate the above option. After using forum in this way for almost 3+ years, the above change was like turning the world upside down. Alternatively, this might be better solution for what you are asking:
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This button will take you to the last post of the thread.