MAMA/FAMA

What is MAMA/FAMA?

MAMA is John Ehlers' MESA Adaptive Moving Average, published in 2001; FAMA, the Following Adaptive Moving Average, is its companion line. MAMA is an EMA whose smoothing factor is recomputed every bar from the rate of change of the dominant cycle's phase, measured with a Hilbert Transform discriminator. When phase rotates quickly, meaning price is behaving cyclically, the factor is forced toward its slow limit and the line goes nearly flat, ignoring the swings. When phase advance stalls because price has broken into a directional move, the factor snaps toward its fast limit and the average jumps to price. The result is a distinctive stair-step ratchet.

FAMA is an EMA of MAMA run at half of MAMA's current factor, so it covers ground at half the speed and acts as the signal line. Ehlers' published bounds are a fast limit of 0.5 and a slow limit of 0.05. Because the pair is built to separate only when price genuinely moves, their crossovers were designed to whipsaw less than fixed-length moving average crossovers; ranging markets can still produce failed signals.

How traders use it

• As a crossover system: MAMA above FAMA is the conventional long bias and below is the short bias, with the adaptive factor intended to keep signals sparse in cycle mode.
• As a regime read: wide, ordered separation between the lines is treated as trend, while braided flat lines are treated as cycle conditions better suited to mean-reversion tactics.
• As an adaptive smoothing core in other tools, replacing a fixed length so downstream logic inherits the fast-attack, slow-decay behavior.