jm §KÜ2-Cï{}Âu+qÂ?#»¥«LHello Roger, Open Bazaar is a decentralized market place but not for trading Crypto. Bisq is exactly what you're looking for. Check it out.
https://whatsonchain.com/tx/2839ee40510394e2c7796725b4fa1d141925fc8df105c87857de3a2ec63ed168