Elastic Volume-weighted MA

What is an Elastic Volume-weighted MA?

The elastic volume-weighted moving average (eVWMA), introduced by Christian Fries, is a recursive average in which volume sets each bar's influence. Each update scales the prior value by (N minus volume) over N and adds price scaled by volume over N, where N is a chosen volume budget. Structurally it is an EMA whose smoothing constant is the bar's share of that budget instead of a fixed number: heavy bars move it sharply, quiet bars barely move it, and a zero-volume bar leaves it unchanged.

Fries published the method in Technical Analysis of Stocks & Commodities in 2001, starting from a criticism of conventional averages: an SMA or EMA runs on a clock of bars, so an illiquid afternoon counts as much as a frantic open. The eVWMA instead measures its memory in shares or contracts changing hands; a bar transacting ten percent of the budget rewrites ten percent of the line, whatever the calendar says.

Fries proposed setting N to the number of shares outstanding, under a model in which each trade randomly replaces existing holdings; the line then approximates the average price at which the current shareholder base acquired its shares. That makes the eVWMA a cost-basis reading, closer in spirit to an anchored volume-weighted average price than to a fixed-window average. Where float data does not exist, implementations substitute a multiple of recent cumulative volume, and that choice dominates the line's speed.

The result is an average that self-regulates across regimes without retuning: in a fast, high-participation market it behaves like a short average and hugs price, while in a dull one it lengthens, refusing to chase drift on thin trade. That places it alongside adaptive designs such as the adaptive-lookback MA, though it adapts to participation rather than volatility. Community implementations range from everget's straight port to LazyBear's envelope build and Spreadburn's trend-colored variant.

How to identify the eVWMA on a chart

The eVWMA plots as a single overlay line, so identification is less about shape and more about recognizing its volume-driven behavior.

1. 1Apply an eVWMA indicator to the price panel; it renders as a smooth overlay comparable to an exponential average of moderate length.
2. 2Watch high-volume bars: the line jumps toward price far more than a fixed-period average would, since a heavy bar consumes a big share of the budget.
3. 3Watch quiet stretches: the line flattens and glides, staying put through low-volume drift and thin sessions.
4. 4Overlay a conventional average of similar speed; the two track closely while volume is steady and separate sharply after volume shocks, the eVWMA's signature.
5. 5Check the volume budget N (shares outstanding, or a lookback times a multiplier); that single input decides whether the line reads fast or slow.

How it's calculated

A moving average whose smoothing weight on each bar is that bar's share of recent volume rather than a fixed constant.

Published by Christian Fries in 2001; the original sets N to the instrument's share float, and platforms commonly substitute an n-bar volume sum.

Each bar replaces a volume-proportional fraction of the prior average with the current price, so the average adapts quickly on heavy volume and barely moves on thin volume.

How traders use it

• As a participation-weighted trend line: slope, side-of-line and crossover logic all work as with any average, with the property that only volume-backed moves relocate the line quickly.
• As a cost-basis proxy: with a float-scale budget, price stretched far above the eVWMA is read as holders sitting on large open profits, a condition worth knowing, though not a timing signal by itself.
• As a self-adjusting base for bands: envelope versions project percentage bands around the line, an MA envelope whose center responds to activity instead of needing a period tuned per market.
• In crossover systems: a fast and a slow eVWMA, or an eVWMA against a conventional average, give moving average crossovers that thin-trade drift is less able to trigger, filtering breakout attempts that lack participation.
• As dynamic support and resistance: in trending markets, pullbacks toward a rising eVWMA are watched for continuation entries, the standard dynamic S/R via MA playbook run on a volume-aware line.

eVWMA vs other moving averages