Earlier quoted context omitted.
It's still part of the Expedia portfolio. There are a few brands whose stocks are listed separately.
What percentage of TripAdvisor does Expedia still own? The stock looks to be mostly held by various mutual funds although I didn't look very closely and may be missing something.
When you join the company, they will explain you the portfolio of brands and how they link together. A user might leave a site and spend money somewhere else, but it's alright as long as it stays in the family.