There is only one file type that uses the .HYPESYMBOL extension:
Hype Symbol File
Symbol file created by Hype, a program used to create interactive, animated website content with HTML5; stores a reusable component, which contains an element, timeline, action, behavior, or animation.
Hype symbols are useful for sharing identical elements across multiple scenes or at different positions in the same scene. They are reusable and can be triggered independently from other elements in the scene. You can create a symbol through the application's toolbar or menu.
Updated: January 20, 2015