How to stop default link click behavior with jQuery

I have a link on a web page. When a user clicks it, a widget on the page should update. However, I am doing something, because the default functionality (navigating to a different page) occurs before the event fires.

This is what the link looks like:

<a href="store/cart/" class="update-cart">Update Cart</a>

This is what the jQuery looks like:

$('.update-cart').click(function(e) { 
  e.stopPropagation(); 
  updateCartWidget(); 
});

What is the problem?