Pomegra Wiki

Accumulation/Distribution Line

The Accumulation/Distribution Line (A/D Line) is a technical indicator that combines volume and price to measure whether money is flowing into a security (accumulation) or out of it (distribution). A rising A/D line during price advances confirms buying strength; a rising A/D during price declines suggests hidden accumulation.

The formula

The A/D Line is calculated as:

Money Flow Multiplier = (Close − Low) − (High − Close) / (High − Low)
Money Flow Volume = Money Flow Multiplier × Volume
A/D Line = Cumulative sum of Money Flow Volume

Step-by-step:

  1. Position in range — where did the close sit within the day’s high-low range?

    • Close = High: multiplier = 1 (entire day was accumulation)
    • Close = Low: multiplier = −1 (entire day was distribution)
    • Close = midpoint: multiplier = 0 (neutral)

  2. Scale by volume — multiply the multiplier by the volume (high volume exaggerates the effect).

  3. Cumulative — A/D Line is a running total; it only goes up, down, or flat (never resets daily).

Intuition: volume-weighted price location

The A/D Line asks: On days when price rose, how much volume was there? And on days when price fell, how much volume was there?

Bullish signal:

  • Price rallies on high volume (strong accumulation), or
  • Price declines on low volume (weak distribution)
  • A/D Line rises, confirming the move

Bearish signal:

  • Price rallies on low volume (weak accumulation, possibly distribution in disguise), or
  • Price falls on high volume (strong distribution)
  • A/D Line falls or lags price, suggesting trouble ahead

Example: accumulation-distribution divergence

A stock rises from $100 to $110 over a month:

Scenario 1 (bullish):

  • Weeks 1–3: price up on high volume; A/D Line rises strongly
  • Week 4: price stalls; A/D Line levels off
  • Interpretation: Strong accumulation early; now exhausted. Likely consolidation, then higher

Scenario 2 (bearish divergence):

  • Week 1: price up on low volume; A/D Line barely rises
  • Week 2–3: price up on declining volume; A/D Line rises minimally
  • Week 4: price up on tiny volume; A/D Line flat or declining
  • Interpretation: Weak accumulation despite price rise. Distribution is happening; rally is vulnerable. Reversal likely.

In Scenario 2, the A/D Line “diverges” from price—price is up but A/D is flat/down. This is a classic warning sign.

A/D vs. on-balance volume

The A/D Line and On-Balance Volume (OBV) are similar but distinct:

MetricA/D LineOBV
CalculationPosition in range × volumeAll up volume added; all down volume subtracted
Edge caseIf close = midpoint, no net signalEvery bar is +vol (up) or −vol (down)
SensitivityRewards closes at extremes of rangeAll-or-nothing: up or down
DivergenceCan flag distribution even in sideways marketsCleaner for trend confirmation

Both serve the same purpose: confirm whether volume is accumulating or distributing. A/D is more nuanced about where in the range the close is.

Use in trend confirmation

A rising A/D Line during an uptrend confirms the trend is healthy. A declining A/D during an uptrend warns the trend may be weakening. Many technical traders use A/D as a secondary filter:

  • Entry — buy a breakout only if A/D Line is rising (not falling)
  • Exit — if A/D turns down while price is still up, exit the position (take profit)
  • Fade a move — if A/D is down while price is up, fade (bet on reversal)

Divergence trading

The most powerful use of A/D is divergence:

Bullish divergence:

  • Price makes a lower low, but A/D Line makes a higher low
  • Interpretation: Despite weakness, accumulation is happening; bounce is likely
  • Action: Buy (or cover short)

Bearish divergence:

  • Price makes a higher high, but A/D Line makes a lower high
  • Interpretation: Despite strength, distribution is happening; decline is likely
  • Action: Sell (or take profits)

These divergences often precede significant reversals, giving traders a 3–7 day lead time on larger moves.

Limitations and false signals

  1. Lagging indicator — A/D is cumulative, so it is slower to reverse than price. A fast reversal may not show up immediately.

  2. Gap risk — A/D doesn’t account for overnight gaps or gaps at market open. If a stock gaps up on low volume, A/D still shows accumulation (close near high), even though no intraday buying occurred.

  3. False divergences — divergences can fail. A stock in a strong uptrend may have A/D divergences (distribution) but still rally for weeks. Divergences work best at cycle extremes (local tops/bottoms), not in the middle of trends.

  4. Sector and timeframe dependent — some sectors or timeframes (e.g., penny stocks) see high false-positive divergences. A/D works better on liquid, established equities.

Integration with other indicators

Most traders use A/D alongside:

A divergence on A/D that is not confirmed by other indicators is weaker.

A/D Line and market breadth

For broader indices (S&P 500, Russell 2000), the A/D Line (summed across all stocks in the index) is a breadth indicator. A rising A/D breadth with a rising price index confirms the move. A falling A/D breadth with rising price signals ** breadth divergence**—not all stocks are participating, and the rally is fragile.

Wider context