Unlike stock markets where there are a couple of major exchanges per country the cryptocurrency sector has 100’s of exchanges and now liquidity providing token swapping networks.
The prices and transaction rates vary across these networks and getting the big picture across these networks to compare prices of tokens and the prices of individual swaps are challenging. To fill these gaps two classic aggregators have taken shape in the market. The first one called Matcha which compares prices across different exchanges, and swapping exchanges, etc., and gives one the ability to connect and exchange one token for another. Visit matcha.XYZ and use it.
Here a video for matcha https://www.youtube.com/watch?v=KDhMRFSRtwQ&feature=emb_rel_end
The next major aggregator is this software tool called 1inch.exchange which enables users to look at the prices across several swapping exchanges which are backed by liquidity pools. These aggregators not create a layer above the traditional marketplace but also facilitate arbitrage where a user can buy off one decentralized exchange and trade at a more favorable exchange – extracting the difference for a profit.