Uber beat Q3 estimates with revenue up 20% to $13.5 billion and adjusted EBITDA rising 33% to $2.3 billion. However, shares slipped 5% in premarket after the company guided Q4 adjusted EBITDA of $2.41-$2.51 billion, slightly below the $2.49 billion consensus. Gross bookings are expected to grow 17-21% to as much as $53.75 billion.