VIX is a trademarked ticker symbol for the CBOE Volatility Index. It measures the predicted volatility of the stock market over a certain period in the future. According to Wikipedia, it was first developed and described by Menachem Brenner and Dan Galai in 1986. At that time, Professor Brenner, in addition to his work at New York University, participated alongside me as a market-maker on the floor of the New York Futures Exchange Trading Options on the New York Stock Exchange Index.