Expedia Group fell the most in 14 years on Thursday and TripAdvisor Inc. dropped the most in two years after the companies reported dismal third-quarter results and laid the blame on Google. Booking Holdings Inc.’s shares dropped 8%, too, wiping out a combined market value of more than $13 billion from the three online travel agents.

Google dominates the online search market, with at least three quarters of the market. People use the search engine to research trips, so for at least a decade online travel agents have refined their websites with trustworthy content and easy booking tools to show up high in Google results.