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The default (and only) "hv" volatility forecast is based on the assumption that today's volatility will hold for the next M days.

To use this script, only one step is mandatory. You must first select days to expiration. The script will not do anything until this value is changed from the default (-1). These should be CALENDAR days. The script will convert to these to business days for forecasting and valuation, as trading in most contracts occurs over ~250 business days per year.

Adjust any other variables as desired:

model: the volatility forecasting model

window: the number of periods for a lagged model (e.g. hv)

filter: a filter to remove forecasts from the sample

filter type: "none" (do not use the filter), "less than" (keep forecasts when filter < volatility ), "greater than" (keep forecasts when filter > volatility )

filter value: a whole number percentage. see example below

discount rate: to discount the expected value to present value

precision: number of decimals in output

trim outliers: omit upper N % of (generally itm ) contracts

The theoretical values are based on history. For example, suppose days to expiration is 30. On every bar, the 30 days ago N deviation forecast value is compared to the present price. If the price is above the forecast value, the contract has expired in the money; otherwise, it has expired worthless. The theoretical value is the average of every such sample. The itm probabilities are calculated the same way.

The default (and only) volatility model is a 20 period EWMA derived historical (realized) volatility . Feel free to extend the script by adding your own.

The filter parameters can be used to remove some forecasts from the sample.

Example A:

filter: <any>

filter type: none

filter value: <any>

Default: the filter is not used; all forecasts are included in the the sample.

Example B:

filter: model

filter type: less than

filter value: 50

If the model is "hv", this will remove all forecasts when the historical volatility is greater than fifty.

Example C:

filter: rank

filter type: greater than

filter value: 75

If the model volatility is in the top 25% of the previous year's range, the forecast will be included in the sample apart from "model" there are some common volatility indexes to choose from, such as Nasdaq ( VXN ), crude oil ( OVX ), emerging markets ( VXFXI ), S&P ( VIX ) etc.

Refer to the middle-right table to see the current forecast value, its rank among the last 252 days, and the number of business days until

expiration.

NOTE: This script is meant for the daily chart only.

Release Notes:
added the straddle (0 stdev)

Release Notes:
puts (bottom right) and calls (top right) are now displayed simultaneously.

Release Notes:
fixed math in puts

Release Notes:
made tables visually symmetrical

- added current volatility (model and value) to a table in the center right

- added a filter

The first two are essential for the new filter feature. The filter removes data points from the sample. For example, if set to "less than" and "0.4" (as in the sample chart), the sample will exclude all forecasts made when volatility exceeded 40%. In this natural gas example, the historical volatility model is over 40% a good deal of the time, so the sample is reduced from about ~7,500 to ~1,500, making the theoretical values are quite different.

Release Notes:
- fixed historical vol annualization

Release Notes:
forgot to add "rank" to the list of options... corrected

Release Notes:
fixed another bug with percentrank

Release Notes:
the forecast lines now reach to the proper expiration day

Release Notes:
- annualized with 252 periods per year by default

- some other defaults changed

- some other defaults changed

Previously, the results reflected a situation in the trader would go back in time and cancel their trade when volatility rose. This is an example of look-ahead bias.

- Filter: model

- Filter type: greater than

- Filter value: 20

Means: only count trades taken when the model's current value was greater than 20. If the model is VIX, this might be a common value for equity option short volatility traders.

- removed tnx (which was 10 year yield, not a volatility index... unfortunately, the real 10 year note volatility index, TYVIX, is not updated anymore)

(also, forgot to mention that I changed "window" default to 20, as it is used with HV. HV20 is similar to IV30, as there are about 20 trading days in a calendar month).

- parameters grouped together