Google's introduction of AI-driven travel planning tools has led to a decline in travel and airline stocks. The new features include expanded flight deal options and a roadmap for comprehensive booking through an AI interface. This development caused shares of Expedia, Booking Holdings, United Airlines, and Delta Air Lines to fall by 6.5%, 4.3%, 5.6%, and 4.4% respectively. Meanwhile, Alphabet's stock rose by 2.8% following news of a $5 billion investment by Berkshire Hathaway in the third quarter.