Booking, Airbnb and Expedia lost $22.5 billion in two days after Meta's Muse. Marriott rose.

$BKNG, $ABNB and $EXPE lost a combined $22.5 billion in market value over the S&P 500's sessions on 22 and 23 September. Over the same two days hotel operator $MAR rose 2.63%, and $HLT closed essentially where it started.

Those two days came straight after Meta's stock jumped more than 11% on excitement over its personal AI agent, Muse. During the 22 September session Barron's ran the headline "Meta's Muse Can Book Your Vacation—and Travel Stocks Are Paying the Price." By the close on the 23rd the booking platforms had fallen 7.5% to 10.3%. The hotel chains had not.

The two days, company by company

The index itself was flat on the 22nd, down 0.03% cap-weighted, which makes the first leg of the drop hard to put down to the tape. The 23rd was a broader down day: the S&P 500 fell 0.77% and 328 of its 500 members closed lower. The booking stocks fell between six and ten times as far as the index did that day.

How unusual the 23rd was

We keep daily price history for every S&P 500 member going back to September 2025. Measured against it:

• Airbnb's 7.56% fall was its worst single day in that whole history. The previous worst was −7.03% on 3 February 2026.
• Expedia's 7.72% fall was its fifth-worst day in the period, and Booking's 5.07% fall its fifth-worst.
• On only one other session in that history did all three fall 5% or more on the same day: 3 February 2026, when Expedia fell 15.26%, Booking 9.32% and Airbnb 7.03%.

The order of events

The sequence matters, because the stocks did not all move when the news first broke.

21 September. Meta rose more than 11% in a session The Motley Fool summed up as Meta surging on excitement over Muse. In our snapshot that added $193.7 billion to its market value, on a day the S&P 500 rose 1.51%. It was Meta's largest one-day gain in our price history. The booking stocks barely noticed: Booking and Airbnb each rose 0.37% and Expedia rose 0.60%.

22 September. Barron's published its piece tying Muse to the travel stocks during the session. Airbnb fell 3.01% and Booking 2.55%. Expedia was nearly flat, down 0.11%. After the close, Seeking Alpha reported that Expedia had announced a partnership with Muse.

23 September. Expedia, the one company in the group that had just announced it would work with Muse, fell the most of the three that day, down 7.72%. Yahoo Finance and 24/7 Wall St. ran the headline "Travel Booking Stocks Tumble as Muse Threatens to Bypass Them." Reuters wrote that Muse had rekindled fears over winners and losers from personal AI agents.

We can line these events up by date. We can't tell from price data which of them any individual seller was reacting to.

The split the map shows

On the StockTreeMap view of the 23rd, Consumer Discretionary was one of the redder blocks, down 1.15% cap-weighted and $105.1 billion in market value. Most of that dollar figure was $AMZN, down 2.24% and $61.6 billion on its own. The three booking platforms together accounted for $16.2 billion of it, about 15% of the sector's loss.

The more telling contrast is inside the travel industry, between companies that take a cut of a booking and the hotel brands behind the room:

• Intermediaries. Booking, Airbnb and Expedia sit between the traveller and the hotel or host. They were down 7.5% to 10.3% over two days.
• Properties. Marriott and Hilton operate or franchise the hotels. Marriott rose on both days; Hilton ended the two sessions flat.

Airlines are messier. $UAL fell 3.90% and $DAL 2.59% on the 23rd, a broad down day, after both had risen on the 22nd. Over the two days United was down 3.21% and Delta 0.91%. Neither pattern resembles the booking platforms' fall, which started on the flat day before.

What the numbers don't say

Two days of prices say nothing about whether Muse will actually take bookings away from any of these companies, or on what timeline. What they do show is where the market repriced first. It marked down the three S&P 500 companies whose business is putting a traveller in front of a room. It left the two big hotel brands alone, and Marriott closed higher on both days.

Meta, for its part, rose another 1.02% on the 23rd, adding $19.1 billion. That was more than the $16.2 billion the three booking platforms lost between them that day.

Figures are from StockTreeMap's end-of-day S&P 500 snapshots for 21, 22 and 23 September 2026 and our daily price history from September 2025. Changes in market value are measured from each company's previous close. This post describes market data and is not investment advice.