When I was in middle school we had trade rings for Littlest Pet Shops and Sillybandz.
Omg when my sister was in 4th grade she was all in on that sillybandz shit. Had them going up and down her arms and traded with fuckin everyone, those things were serious business.
These days it’s all about slime. There was legitimate underground slime ring at the school I work at, complete with children stealing bottles of glue from the art room to make their supply of contraband.