Shares of Booking Holdings (BKNG) fell 3.8% in the afternoon session after the European Commission initiated formal proceedings to investigate potential breaches of the Digital Services Act. The inquiry specifically evaluates whether Booking.com adequately assessed and mitigated risks from fake listings and phishing scams, as well as examining if the platform failed to clearly label paid search rank placements as advertisements. Executive Vice-President Henna Virkkunen noted that European consumers require protection from fraudulent practices under the Digital Services Act, which imposes specific responsibilities on leading services. This heightened regulatory scrutiny introduces legal uncertainty for Booking Holdings, raising investor concerns over potential penalties and the necessity for required adjustments to its European operations. Following the initial drop, BKNG shares shed some losses and rose slightly to $158.11, trading down 3.6% from the previous close. The market appears to view this regulatory news as meaningful but not fundamentally altering its perception of the business, especially given the stock's history of volatility with 14 moves greater than 5% over the last year. Booking Holdings is currently down 25.8% since the beginning of the year and trades 28% below its 52-week high of $219.68 from January 2026. Despite the recent decline, long-term investors who purchased shares five years ago would now see an investment worth $1,639 for every $1,000 originally invested.