Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of travel service TripAdvisor (TRIP -3.16%) were getting five stars from investors, gaining as much as 23% after John Malone's Liberty Interactive (QVCA) purchased TripAdvisor Chairman Barry Diller's nearly 5 million shares for $62.50 apiece.

So what: Diller had acquired TripAdvisor as part of Expedia (EXPE 0.49%) in 2004, and spun it off from the larger travel services company last year. Some are now speculating that Malone will also buy out Diller's shares of Expedia, which jumped as much as 5% on today's news. Liberty Interactive shares, meanwhile, fell more than 1%, but the deal gives the media company a majority of the voting rights of TripAdvisor.

Now what: With Malone in control of the voting rights, many observers expect him to continue building a stake in TripAdvisor, as he's done recently with Sirius XM Radio. The more than 50% premium Malone paid should indicate he'd have no qualms about buying shares at the current price, near $42. Diller will resign as chairman but remain on as director. Liberty Interactive's other media properties include Evite, QVC, and Gifts.com.

Stay connected on any further developments following the TripAdvisor-Liberty deal.