The Eye of Horus was a symbol used to protect pharaoh in the afterlife and to ward off evil. Exchange ‘afterlife’ with ‘future’, and ‘evil’ with ‘losses’, and implied volatility becomes the trader’s very own Eye of Horus. I usually start my lectures on volatility with a glance at historic volatility. For a good reason. By assessing historic data, we can see how a certain security behaved in the past and from its performance make informed assumptions about future behaviour.