Обернуть все что идет после div

var b = document.querySelector('.block')
var d = document.createElement('div')

while (b.nextSibling) {
  d.appendChild(b.nextSibling)
}

b.insertAdjacentElement('afterend', d)

.block + div {
  border: 1px solid blue;
}

<div class="block">Some text</div>
<hr>
More text
<br>
Again more text

var $b = $('.block')
var $c = $b.parent().contents()
$b.after($('<div>').html($c.slice($c.index($b) + 1)))

.block + div {
  border: 1px solid blue;
}

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

<div class="block">Some text</div>
<hr>
More text
<br>
Again more text

var $b = $('.block')
var $c = $b.parent().contents()
$c.slice($c.index($b) + 1).wrapAll('<div>')

.block + div {
  border: 1px solid blue;
}

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

<div class="block">Some text</div>
<hr>
More text
<br>
Again more text