Constance Brown Studies

What are the Constance Brown Studies?

The Constance Brown Studies are a family of RSI-derived momentum tools from Constance Brown's Technical Analysis for the Trading Professional (1999), each built to repair a specific weakness of RSI rather than replace it. The best known is the Composite Index: as published, the 9-bar momentum of a 14-period RSI added to a 3-bar simple average of a 3-period RSI. Removing RSI's bounded 0-100 scale is the point; the unbounded line can keep stretching where RSI flattens, so it can print divergences that RSI's compression near its extremes hides.

The second study is the Derivative Oscillator: a 14-period RSI smoothed twice, with a 5-period and then a 3-period exponential average, minus a 9-period simple average of that double-smoothed line, plotted as a histogram. Brown also reframed how RSI's operating range shifts between bull and bear regimes; that thread of her work is covered under RSI range rules.

How traders use it

• Cross-checking divergence: the Composite Index is read at RSI's swing highs and lows, and a divergence that shows on one line but not the other is the warning, the Composite catching what RSI's bounded scale conceals.
• Timing momentum flips with the Derivative Oscillator histogram: zero-line crosses and shrinking bars carry the same grammar as a MACD histogram, applied to double-smoothed RSI.
• Trigger construction: Brown plotted the studies with moving averages of themselves, so a study crossing its own average adds a mechanical trigger to the divergence read.