Bollinger / Keltner Bands

What It Does

Bollinger / Keltner Bands runs on a single contract at daily bars. On every session close it computes a volatility envelope around price (either a Bollinger Band over closes or a Keltner Channel over highs, lows, and closes) and acts on where the close finished relative to the bands.

The mode parameter picks one of four behaviors:

• bb_fade: close at or below the Bollinger lower band enters long, close at or above the upper band enters short. Exit when close crosses back through the middle SMA.
• bb_break: close crosses up through the Bollinger upper band enters long, close crosses down through the lower band enters short. Exit when close crosses back through the middle SMA.
• kc_fade: same as bb_fade, on the Keltner Channel. Middle is the EMA.
• kc_break: same as bb_break, on the Keltner Channel.

Fade and break are deliberately opposite reactions to the same trigger. Fade treats a band touch as a stretched move that will revert. Break treats a clean cross through the band as a regime shift worth riding. The strategy never combines them; one mode is in effect for an entire run.

Exits are symmetric across all four modes: the position closes when price crosses back through the middle band (SMA for Bollinger modes, EMA for Keltner modes). There are no stops, no targets, no time-based exits. Once a position is open, no new entries fire until it closes.

Why It Works (Sometimes)

Volatility bands are a forty-year-old idea, and the disagreement between fade traders and break traders is older than the indicators. Both are right in the right regime.

In range-bound markets, price oscillating across two standard deviations from a moving average reverts more often than it continues. Fade wins, break loses. In trending or expansion regimes, a clean close beyond the bands more often marks the start of a multi-bar push than the peak of a reversion. Break wins, fade loses.

Neither mode adapts on its own. The presets here are starting points; before relying on any of them, run them through the regime that matches what you actually trade. A Bollinger fade that prints beautiful equity in a chop year can give it all back in a trend year, and the reverse is just as true for the break setup.

Presets

Six presets cover the canonical setups:

• BB Fade 20/2 Both: the textbook setup. Classic 20-period Bollinger Band with 2.0 standard deviations, fade both sides.
• BB Break 20/2 Both: same band, opposite stance. Trade the close-through cross rather than fade it.
• KC Fade 20/2 Both and KC Break 20/2 Both: the Keltner siblings of the two Bollinger presets. ATR-scaled bands expand and contract more smoothly than standard-deviation bands, which changes how often and how cleanly the triggers fire.
• BB Fade Long Only: the textbook fade with shorts disabled. Equity-index futures have historically punished mean-revert shorts; this preset avoids that side.
• Tight BB 20/1.5 Fade: a narrower Bollinger fade that fires more often on smaller moves. Earlier in on a reversion, more exposed to whipsaws when price keeps going.

Use the form to set your own mode, periods, multipliers, and side. The presets are starting points, not endpoints.

Best In

• Markets with clear regime shifts between range and trend. Equity-index futures (NQ, ES) and metals (GC) all show enough regime variation to make the fade-vs-break comparison interesting on the same instrument.
• Daily-timeframe research. Bollinger and Keltner both behave more cleanly on session bars than on intraday data, and the middle-band exit reads naturally as “price returned to fair value”.
• Studies that want a clean band-based baseline before adding regime filters, volatility filters, or position-size rules.

Where It Struggles

• Persistent one-way trends. The fade modes will sell strength all the way up a bull market and buy weakness all the way down a bear market. The break modes do the right thing here, but break is a different strategy with a different equity curve.
• Choppy ranges. The break modes false-fire on every brief excursion through the band and exit on the next reversion through the middle, bleeding small losses.
• Volatility regime changes. A market that expands from a long calm period blows through the bands in either direction with no warning; whichever mode was wrong takes outsized losses before the middle-band exit triggers.
• Persistent skew. The two-sided presets assume both directions pay symmetrically over the test window. In a commodity in structural backwardation, or an index in a sustained drift, one side does most of the work and the other side bleeds.

Possible Uses

• A control strategy for any other band-based idea. A more sophisticated band setup that does not beat the bare fade or break is probably not earning its complexity.
• A regime probe. Running BB Fade and BB Break with the same parameters on the same data and comparing equity curves is a direct read on whether the test window favored reversion or continuation.
• A starting point for layered work. Either mode can be combined with a trend filter, a volatility filter, or a session filter to test whether the basic edge survives the additions.

What It Does Not Do

• No stops, no targets, no time exit. The middle-band cross is the only exit path. If price never crosses back through the middle, the position is held until the strategy is shut down.
• No re-entry while in position. Once long, additional band touches or breaks are ignored until the position closes.
• No mixing of modes. A single run is purely fade or purely break, purely Bollinger or purely Keltner. The four modes are alternatives, not layers.
• No volatility-scaled position sizing. Contracts per trade is a fixed integer.
• No awareness of session or calendar boundaries beyond the daily-bar close. The same rule fires on Monday after a long weekend as on a midweek close.

FAQ

What is the Bollinger / Keltner bands strategy?

It runs on daily bars and trades a volatility envelope around price four ways: fade or break, on either Bollinger Bands or Keltner Channels. Fade treats a band touch as a stretched move that will revert, while break treats a clean close through the band as a regime shift worth riding. All four modes exit when price crosses back through the middle band, with no stops, targets, or time exits. One mode is in effect for an entire run; the strategy never combines them.

Does fade or break work better?

Both are right in the right regime, which is the whole point of offering them side by side. In range-bound markets price reverts more often than it continues, so fade wins and break loses. In trending or expansion regimes a clean close beyond the bands more often starts a multi-bar push, so break wins and fade loses. Running both modes with the same parameters on the same data is a direct read on whether your test window favored reversion or continuation, so run the backtest on this page to compare.

When does this strategy struggle?

The fade modes struggle in persistent one-way trends, selling strength all the way up a bull market or buying weakness all the way down a bear market. The break modes struggle in choppy ranges, false-firing on every brief excursion through the band and bleeding small losses. Volatility regime changes hurt whichever mode is wrong, and the two-sided presets suffer when one direction does most of the work and the other side bleeds.