SOURCE

var SCROLL_EVENT_KEY = 'scroll-bounced';
var BOUNCING_DISTANCE = 5;
var DATA_KEY = 'scroll.bounce';

$.event.special[SCROLL_EVENT_KEY] = {
  bindType: 'scroll',
  handle(event){
    if ($(this).data(DATA_KEY) == undefined){
      $(this).data(DATA_KEY, 0) ;
    }
    var offset = Math.abs(window.pageYOffset - $(this).data(DATA_KEY));
    var scrolling = offset < 5 
  	if (scrolling){
    	return
  	}
    console.log(offset)
    $(this).data(DATA_KEY, window.pageYOffset);
    event.handleObj.handler.apply(this, arguments);
  
  }
}

$(window).on(SCROLL_EVENT_KEY,function(){
  const maxScroll = document.body.scrollHeight - window.innerHeight;
  const percentage = window.pageYOffset / maxScroll * 100 + '%';
  $('.scroll-bar-fixed-top').css('width', percentage);
})

<div class="scroll-bar-fixed-top"></div>
<div class="inner"></div>

.scroll-bar-fixed-top{
  position: fixed;
  top: 0;
  height: 4px;
  width: 0;
  background: orange;
}
.inner{
  height: 200vh;
}