People use a low VIX to represent complacency, which is typically present before a market crash, along with the famous irrational exuberance. Once it goes up,

People use a low VIX to represent complacency, which is typically present before a market crash, along with the famous irrational exuberance. Once it goes up, it means there's volatility in the future coming, because the VIX is based on S&P 500 options.