CBOE - Cboe Global Markets, Inc.

Founded in 1973, Cboe controls the largest option exchange in the US, which provides around 60% of the firm's revenue. The company is best known for its proprietary S&P 500 and VIX index options, which it offers through an exclusive contract with S&P Global. The firm moved into US and European equities through the $3.4 billion acquisition of BATS in 2017. Cboe has continued to look to expand internationally, using acquisitions to build a presence in both Canada and Australia.