https://www.cnbc.com/2017/11/07/priceline-tripadvisor-shares-crater-after-weak-profit-outlooks-from-competition-with-airbnb.html >Priceline and TripAdvisor shares both plunged Tuesday after the online travel firms warned about future results because of in increase in spending in response to mounting competition. >Shares of TripAdvisor fell more than 18 percent, on pace for its worst day since Nov. 2016. Priceline fell 10 percent, on track for its worst day since June 2016.