HDX is a token that powers a DEX. The token is the payment mechanism that pays holders of the HDX token in reward for supporting the decentralized exchange. The unique part of the HDX DEX is that it uses layer 2 to action the swaps in DEX that resides inside a custodial wallet. The approach of the DEX is unique to other similar projects that have Layer 2 swaps in the wallet as the HDX DEX has a CEX like trading experience and is designed to be used by high volume bot traders.
HDX is designed to be decentralized and unstoppable, fast and highly scalable. The intention of the DEX is to ensure pairs can be swapped directly with Bitcoin, and Ethereum. Already available pairs are ETH and BTC and this is achieved with a layer 2 swap using the lightning network, and other L2 solutions. The HDX DEX is designed to be blockchain agnostic, the only requirement to have a project listed on the HDX DEX is that it uses a compatible L2 technology, and there are parties on either side of the swap wanting to trade.