Accumulation/Distribution Line
Weights volume by the close's position within the bar's range to build a cumulative measure of buying versus selling pressure.
Overview
The Accumulation/Distribution Line was developed by Marc Chaikin as an improvement over OBV. While OBV assigns all volume to either buying or selling based on the direction of the close, A/D uses the Money Flow Multiplier to prorate volume based on where the close falls within the high-low range. A close at the top of the range assigns more weight to buying pressure; a close at the bottom assigns more weight to selling pressure.
How it looks on a chart
Illustration only — synthetic data generated for visual reference.
The A/D Line is similar to OBV but smarter about how it assigns volume. If a stock closes at the very top of its day's range (e.g., the high is $50, low is $48, and it closes at $49.80), that bar has strong buying pressure. If it closes near the bottom of the range ($48.20), there was strong selling pressure. The A/D Line uses where exactly the price closed within the range to weight the volume accordingly. This makes A/D more nuanced than OBV. A stock can close higher on the day (which would add all volume to OBV) but if it closed in the lower portion of its range, the A/D line might only add a small portion of volume or even subtract some. This tells you more about the real quality of the up-close. Like OBV, you look for the A/D Line to confirm or diverge from price. If price is rising but the A/D Line is falling, buying pressure is weakening — a warning sign. If price is falling but A/D is rising or holding steady, sellers are not actually gaining ground — potential support.
Money Flow Multiplier = ((Close − Low) − (High − Close)) / (High − Low). This ranges from −1 (close at the low) to +1 (close at the high). Money Flow Volume = MFM × Volume. A/D Line = Cumulative sum of Money Flow Volumes. The Chaikin Money Flow (CMF) indicator is derived from A/D: CMF = Sum(Money Flow Volume, n) / Sum(Volume, n). CMF oscillates between −1 and +1 and avoids the non-stationarity problem of the cumulative A/D Line. CMF > 0 indicates net buying pressure over the period; CMF < 0 indicates net selling. Readings above +0.25 or below −0.25 are considered significant. A/D divergence signals are the primary application: bearish divergence (price new high, A/D lower high) warns that despite the price advance, more volume is being distributed (sold) in the lower half of daily ranges. This is a sophisticated warning that even though buyers are winning the day-to-day battle, the overall volume flow is turning bearish.
The A/D Line's Money Flow Multiplier has an interesting relationship to market microstructure. In limit order book theory, closes in the upper portion of the daily range suggest that buy market orders have consumed available sell limit orders more aggressively than vice versa — a proxy for net order imbalance. This connects the A/D to the VPIN (Volume-Synchronized Probability of Informed Trading) concept from Easley et al. (2012). A limitation rarely noted is that the A/D calculation ignores gaps. If a stock gaps up 5% at the open and then sells off to close in the middle of the gap range, the A/D may show neutral (close at midpoint of the new day's range), missing the fact that sellers entirely overwhelmed the gap-up open. OBV, by contrast, would show a full day's positive volume for the gap-up open day. For cross-asset portfolio use, the z-score of CMF over a rolling 20-day window is a useful ranking metric. Assets with CMF z-scores in the top quartile have shown modest but consistent outperformance in academic studies, suggesting that cumulative volume-weighted price position carries predictive information beyond pure price momentum.
Formula
MFM = ((Close − Low) − (High − Close)) / (High − Low) MFV = MFM × Volume A/D Line = Cumulative sum of MFV
- 1.Calculate the Money Flow Multiplier: MFM = ((Close − Low) − (High − Close)) / (High − Low).
- 2.MFM ranges from −1 (close at the low) to +1 (close at the high).
- 3.Compute Money Flow Volume: MFV = MFM × period Volume.
- 4.Add MFV to the running cumulative total to build the A/D Line.
- 5.For Chaikin Money Flow: CMF = Sum(MFV, n) / Sum(Volume, n) over n periods.
Parameters
| Parameter | Default | Range | Description |
|---|---|---|---|
| CMF Period | 20 | 5–50 | Lookback period for Chaikin Money Flow calculation. |
Trading signals
bullish: A/D Line rising alongside rising price
Volume confirming price advance — healthy accumulation phase.
bearish: Price new high but A/D makes lower high (bearish divergence)
Distribution into strength — selling pressure growing despite price advance.
bullish: CMF crosses above zero
Net buying pressure emerging — period-sum of volume flow turned positive.
bearish: CMF crosses below zero
Net selling pressure emerging — period-sum of volume flow turned negative.
Limitations
- •Ignores price gaps between sessions, which can represent significant buying or selling pressure.
- •Cumulative A/D Line is non-stationary and trend-following — absolute values are meaningless.
- •Money Flow Multiplier is sensitive to the position of the close within a narrow-range bar.
- •Not meaningful for assets with thin volume or inconsistent intraday price data.
Gilito uses the Chaikin Money Flow (CMF) variant of the A/D Line as a volume-pressure feature in its strategy models, comparing its predictive signal to OBV and Force Index on each asset class. A/D divergence detection is automated in its backtesting engine as a confirmation filter for breakout strategies.