The world’s largest options exchange. The Chicago Board Options Exchange (Cboe) was founded in 1973 with contracts focusing on individual equities, indexes, and interest rates. It offers options on more than 2,200 companies, 22 stock indices, and 140 exchange-traded funds (ETFs). It also calculates and disseminates the CBOE Volatility Index (VIX), which measures the stock market’s expectation of volatility based on S&P 500 index options. These and other financial instruments give investors the ability to manage the risk of their individual investment strategies (eg, through put options).