Jumping from bridges into rivers or lakes or bays or other bodies of water ...
Jumping to conclusions, often wrong, when you don't have all the information you need to make the correct decision, or much of that information is wrong.
Jumping out of a plane? Make sure you're wearing a parachute.
Jumping for joy? What a cliche. Celebrate like an adult. Please.
Jumping jack? The exercise? The picture above is poor form for it.
Jumping beans? From Mexico. And they do exist. Please clink the link here if you want more information.