Trending helps viewers see what’s happening on YouTube and in the world. Some trends are predictable, like a new song from a popular artist or a new movie trailer. Others are surprising, like a viral video. Trending aims to surface videos that a wide range of viewers will appreciate.
Trending is not personalized. Trending displays the same list of trending videos in each country to all users, except for India. In India, Trending displays the same list of trending videos for each of the 9 most common Indic languages. The list of trending videos is updated roughly every 15 minutes. With each update, videos may move up, down, or stay in the same position in the list.
What determines if a video is ranked on Trending?
Amongst the many great new videos on YouTube on any given day, Trending can only show a limited number. Trending aims to surface videos that:
- Are appealing to a wide range of viewers
- Are not misleading, clickbaity or sensational
- Capture the breadth of what’s happening on YouTube and in the world
- Ideally, are surprising or novel
Trending aims to balance all of these considerations. To achieve this, Trending considers many signals, including (but not limited to):
- View count
- The rate of growth in views
- Where views are coming from (including outside of YouTube)
- The age of the video
We combine these signals to produce a list of videos that showcases what’s happening on YouTube and in the world. This means that the video with the highest view count on a given day may not be #1 on Trending, and videos with more views may be shown below videos with fewer views. Even if your video meets all the above criteria, it may not appear on Trending, as many other videos may also meet those criteria. The Trending system tries to choose videos that will be most relevant to our viewers and most reflective of the broad content on the platform.YouTube does not accept payment for placement on Trending. We do not include views from YouTube ads in selecting videos for Trending. YouTube does not favor specific creators.
Source : https://support.google.com/youtube/answer/7239739?hl=en