There could be many reasons. Not being a cryptocurrency analyst I could not tell you for sure. Hive account@splinterlands could be a factor. Also Hive account@leofinance and its new Cub Finance yield farming platform. NFT Showroom and other projects? New users building their stakes? There are so many things going on.

One must remember that a large amount of HIVE is on external exchanges as well. Speculation and day trading also plays a part. I don't think there is just one thing that a person could put their finger on.