Additionnaly of atomicswaps and haveno-reto.com, if you want to really impact the market, you need to know most of people are tracking their crypto prices on things like coinmarketcap and coingecko.
Those trackers, aren't tracking DEX and tracking CEXs with manipulated reserves, with leverage ect ect. But they lists few nonkyc exchanges where price can be impacted with less risks like kyc shotguns ect.. for example i'd advise tradeogre.