Hull Moving Average Bollinger Bands: a faster middle line for the bands
Hull Moving Average Bollinger Bands keep the usual band width, a multiple of the standard deviation, but swap the slow simple average in the middle for a Hull Moving Average. The middle turns sooner, so the envelope bends with price instead of trailing behind it.
What it measures
Classic Bollinger Bands centre on a simple moving average. After a sharp turn that average lags, the bands point the wrong way for a while, and price looks stretched against a middle line that simply hasn't caught up.
The formula in words: the middle line is the Hull Moving Average of the close over your chosen length. The upper band is the middle line plus a multiplier times the standard deviation of the close over the same length, the usual measure of how widely closes spread; the lower band is the middle line minus the same amount. You choose the multiplier. Only the middle changes; the width is calculated as in normal bands.
Which leaves a slightly odd object: the width still describes spread around a simple mean, while the middle leans forward.
How it behaves in real markets
In a trend on ES the faster middle keeps price nearer the centre, so outer-band touches are rarer and mean more. After a reversal the bands turn within a few bars, so band-based exits react sooner.
The weakness is chop. The Hull line overshoots on sharp spikes, and here the whole envelope overshoots with it. In a tight range the bands wiggle around price and a mean-reversion rule gets fewer clean setups.
Common ways to use it (concepts)
Band walk with a faster middle
Treat closes outside the upper band as strength and exit on a close back below the Hull middle. You get out earlier than with a classic band exit.
Narrow bands, then expansion
The width works as in normal bands, so squeeze rules carry over. The Hull middle often tilts toward the breakout side first.
Back to the middle in a trend
A pullback to the Hull middle that holds is an entry. It comes sooner than a pullback to a simple average, and so does the false one.
Pairing it with other indicator families
This band already mixes a trend line and a volatility measure. I'd skip stacking another moving average on top and add a regime filter instead: ADX or the Choppiness Index can switch band fades off in trends and band walks off in ranges.
Compare it with classic Bollinger Bands and with Keltner Channels, whose width comes from ATR. If the Hull version doesn't beat the classic one out of sample on your contract, the extra speed isn't worth the extra noise.
In AlphaPrime
AlphaPrime has the Hull Moving Average and Bollinger Bands as separate built-in families, and the strategy generator can already put a Hull rule and a Bollinger rule in one strategy. A band drawn around the Hull line itself is not built in; ask the AI to add it as a custom indicator and it appears under Custom indicators.
Run the Hull version and the classic version in the same job before you trust either. The free seven-day trial is enough for a first comparison.
FAQ
Are Hull Bollinger Bands better than normal Bollinger Bands?
Faster, not automatically better. They react sooner after turns and overshoot more in chop. Judge both on the same contract, out of sample.
Should the standard deviation be measured around the Hull line?
Some versions do that, which gives narrower bands in trends. It is a different indicator and worth testing as one.
What length should the Hull middle use?
Start with the length you use for normal bands so the two versions compare fairly, then let the generator test others.