(Reuters) -Activist investor Starboard Value disclosed a 9% stake in Tripadvisor ( TRIP ) on Thursday, saying the online travel booking platform's shares were "undervalued".

The hedge fund, one of the industry's busiest activist investors, said it will engage with Tripadvisor's ( TRIP ) management about opportunities for value creation, sending the online travel firm's shares up 10% in premarket trading.

Starboard said it purchased Tripadvisor ( TRIP ) shares as it believed they "were undervalued and represented an attractive investment opportunity," according to a filing with the U.S. Securities and Exchange Commission on Thursday.

Tripadvisor ( TRIP ) did not immediately respond to Reuters' request for comment.

Starboard's stake was worth about $160 million, according to Reuters' calculations based on its last closing price.

The travel platform's shares have risen 1.5% so far this year, compared with a 10.5% gain in the Dow Jones U.S. Travel and Leisure Index.

The stock currently trades at 7.93 times the average estimate for its earnings for the next 12 months, compared with an industry median of 16.22, according to LSEG data.

In December 2024, Tripadvisor ( TRIP ) entered a merger agreement to repurchase all shares of its then-controlling shareholder, Liberty Tripadvisor Holdings, and now runs as an independent company.

Starboard has pushed for changes at several companies in the last one year, including Band-Aid maker Kenvue, drugmaker Pfizer ( PFE ) and design-software firm Autodesk ( ADSK ).