So you would hang on to a 20 year bond,issued on 2014...with a coupon of (lets say) 4% and currently trading at (I am Catstimating here) $1100 (ie 10% above par) ??
If rates go to 5% that thing will be worth maybe $700...

FYI Good info/Twitter feed on bonds;

https://twitter.com/tracyalloway?lang=en