What is the largest crypto exchange in the UK?

Could you elaborate on the identity of the largest cryptocurrency exchange operating in the United Kingdom? Given the vast array of platforms available, it's crucial to determine which one holds the largest market share and trading volume. Is it a well-known international exchange that has established a strong foothold in the UK, or is it a domestic player that has grown rapidly? Additionally, what factors contribute to its dominance, such as its user-friendliness, security measures, or the range of cryptocurrencies it supports? Understanding the market leader in this space could provide valuable insights for investors and traders alike.