What most likely happens in the long run after you've made your jump rings or loops and have a finished piece of jewelry, is the wire end can have a slight gap that grows over time and comes undone. BAM! All your goodies in that jump ring or loop ends up on the floor ruining your day. So, you want to make sure your loops are securely closed as seen in the bottom loop of the picture below.
I know, I know.... we all get in a hurry and don't want to pick up another tool just to cut wire, but trust me, you'll be glad you developed this habit. And if you've been having issues with jump rings or loops staying closed, try these cutters and see what a huge difference they make!