Friendica (formerly Friendika, originally Mistpark) is a free and open-source software distributed social network. It forms one part of the Fediverse, an interconnected and decentralized network of independently operated servers.
Of course, I can’t check if every instance is trade-free, but in general I think you can say that friendica is a trade-free social network. I registered an account at https://opensocial.at/ and there are no trackers or ads. Mind you, many instances have a bad “health score” and some might not work, so you want to pick one with a good “health score”.