The latest version of Vivaldi now includes a tacker blocker developer by DuckDuckGo. The tool, which is powered by DuckDuckGo's Tracker Radar software, makes browsing the Internet a bit more private out of the box. However, other privacy-focused extensions should still be used.
https://www.notebookcheck.net/Vivaldi-browser-3-0-uses-DuckDuckGo-s-tracker-blocker.462287.0.html