I invested into Expedia in February 2018 after the stock had become cheap enough. The idea was that a stock in a secular growth sector (online travel) should do well in the long run. After pretty decent fulll year 2018 numbers, with double digit increases in both, top and bottom, line, the first quarter 2019 showed a clear slowdown. Topline growth slowed to ~4%. Excluding Trivago which is still shrinking, topline sales would have grown +6%. Underlying profitability has improved although the first quarter is always the weakest one.
What I found interesting is the fact that Expedia performed better than Booking com. Here is a stock price comparison (including Tripadvisor and Trivago):