Larry Connors %B Strategy: A Simple Mean Reversion Edge Explained

Key Takeaways

• %B >1 indicates price above upper Bollinger Band
• %B <0 signals price below lower band, a buy signal in uptrend
• Strategy trades only 4% of time, yielding 1.3% average gain per trade
• Requires market above 200‑day moving average to filter direction
• Backtest 1993‑2024 on SPY produced 63 trades with high win rate

Pulse Analysis

The %B indicator, a by‑product of Bollinger Bands, translates price position relative to the bands into a normalized scale from 0 to 1, extending beyond the bands to negative or greater‑than‑one values when price breaches the limits. This linear representation makes extreme readings instantly recognizable, a feature that appeals to quantitative traders seeking clear entry thresholds. In a mean‑reversion context, %B values below zero flag an oversold market, while values above one flag overbought conditions, allowing systematic capture of short‑lived price corrections.

Larry Connors distilled this insight into a concise rule set: trade only when the broader market is above its 200‑day moving average, wait for %B to dip below zero, take a long position, and exit after a few days of price recovery. His backtest on the SPY ETF from 1993 through 2024 recorded just 63 trades, each delivering an average 1.3% profit while the portfolio was invested a mere 4% of the time. The low turnover reduces transaction costs and slippage, turning a modest edge into a compelling risk‑adjusted return.

Because the %B strategy hinges on clear statistical extremes and a simple trend filter, it can be automated across a broad universe of liquid equities without heavy data requirements. However, its performance is tightly bound to equity markets; commodities or crypto assets often lack the same mean‑reversion dynamics, leading to weaker results. Traders should also monitor volatility spikes that can push %B far beyond the -1/2 thresholds, increasing the risk of false signals. When applied prudently, the approach offers a low‑frequency, high‑conviction tool that complements longer‑term portfolio strategies.