Booking Holdings shares tumbled after it gave a forecast for profit in the current period that missed analysts’ estimates as the company spends more on marketing and advertising for its home-rental listings.

The increased spending will reduce Booking Holding's earnings
but are crucial for the company's “long-term growth and to drive more and better brand awareness”, CEO Glenn Fogel said.

Booking’s Q4 results beat Wall Street projections, however, as gross travel bookings rose 9 percent. The company reported revenue of $3.21 billion for the fourth quarter, and expects hotel room nights booked will increase 6% to 8% in the first quarter of 2019.

Alternative accommodations now 20% of Booking Holdings' total revenue