Computing Current Volatility

Answer:

There are a number of ways to calculate an estimate of the current volatility:

1. Using parametric and non-parametric models
2. Intraday tick data
3. Implied volatility in option markets, etc.

Using a GARCH model, the user computes the model-fitted volatility and treats the last value as an estimate for current volatility.

https://www.jstor.org/stable/4479451