The annualised volume of Crypto Exchange markets reaches the trillion dollars threshold. Due to the dispersed and decentralised nature of this market, in which each Crypto Asset trading platform works as an independent dark pool, official statistics is unavailable and there is little private research data. The objective of this paper is to present a brief overview of the global Crypto Exchange market, providing an inventory of the available Crypto Exchanges as of the end of 2018, and compare the most relevant in both quantitative and qualitative terms. From a sample representing 99 % of a daily global market share, measured by trading volume, a Key Performance Indicator system is proposed and tested to evaluate the level of corporate governance (or 'crypto governance') observed at each Crypto Exchange. The outputs are compared with average fees and individual market shares. The results obtained from market data provide evidence that most of the volume is traded at Crypto Exchanges with lower governance scores, while those ranked with higher governance scores charge, on average, higher trading fees.