The top 10 trending keywords registered in .COM and .NET domain names during the month of February 2019 were published by Verisign, the .com and .net registry.
You can find the list from last month here.
My experience shows that 700 or 800 (or even less) domain registrations are enough to bring a keyword into the top 10.
There was on common keyword in the 2 lists: apex.
The “Apex Legends” domain name registrations are related to a free-to-play battle royale game developed by Respawn Entertainment and published by Electronic Arts. It was released for Microsoft Windows, PlayStation 4, and Xbox One on February 4, 2019, without any prior announcement or marketing. So that might explain the sudden increase in domain registrations. Of course there could be trademark (TM) problems with these domains.