Bisq exchange was launched back in 2014. At that time it was one of the first Decentralized Autonomous Organizations (or simply DAO). According to the founders of this exchange, one of the goals of Bisq network is to "keep the original spirit of Bitcoin alive".
Trade.io (currently (TIOmarkets) is a centralized trading platform. In October, 2019, the Trade.io exchange suspended its operation and rebranded in TIOmarkets to be able to provide more markets, such as forex, shares, indexes, metals and cryptos.
Bittrex was founded in 2014 in Seattle, USA. There is also a Bittrex International division, which is based in Europe. The list of coins and pairs is reaching hundreds which is great for many trading opportunities.