jQuery(function($) {
    $(".my-selector").on('scroll', function() {
        if($(this).scrollTop() + $(this).innerHeight() >= $(this)[0].scrollHeight) {
            // at the bottom, do stuff like hide a down arrow
            $(".down-arrow").addClass("hide");
        }else{
            // not at bottom, show down arrow or something else
            $(".down-arrow").removeClass("hide");
        }
    })
});