Volume & money flowAccumulation/Distribution Line · ADL
A cumulative money-flow line that weights each bar's volume by where the close lands within its range.
Works best in trending marketsEngine-computed on a fixed sample series
What it is
The Accumulation/Distribution Line, created by Marc Chaikin, is a running volume-based indicator that tries to reveal whether a security is being quietly accumulated (bought) or distributed (sold) by weighting each bar's volume according to where the close finished within that bar's range. The question it answers is whether the volume flowing through a market supports the price trend or secretly contradicts it. A close near the high of the bar is treated as buying pressure and adds volume to the line; a close near the low is treated as selling pressure and subtracts it. Plotted as a single cumulative line beneath price, it is read mostly for its slope and, above all, for divergences against price.
How it's calculated
For each bar the formula first computes a Money Flow Multiplier: ((Close − Low) − (High − Close)) / (High − Low). This multiplier ranges from +1 when the close is exactly at the high to −1 when it is exactly at the low, and it sits near zero when the close is in the middle of the range. That multiplier is then multiplied by the bar's volume to produce the Money Flow Volume, which is the volume-weighted buying or selling pressure for that bar. Finally, each bar's Money Flow Volume is added to a cumulative running total — the previous line value plus today's Money Flow Volume — so the line is an ever-growing sum. Because it is cumulative, the absolute level is arbitrary; only the direction and shape carry meaning.
Reading it, step by step
A rising line means Money Flow Volume is net positive bar after bar, indicating sustained accumulation; a falling line means persistent distribution. The most prized signal is divergence: when price makes a higher high but the line makes a lower high, buyers are stepping back even as the tape still looks strong, warning of a possible top; the bullish mirror occurs when price makes a lower low but the line turns up. Confirmation is the other read — when the line rises in step with an advancing price, the trend has genuine volume support behind it. Because the level is arbitrary, you never read an absolute number; you read the trajectory and how it lines up with price. A flat line during a price move signals indecisive flow that undermines the move.
Best timeframes and settings
The A/D Line has no period parameter at all — it is a pure cumulative sum — so there are no lengths to tune, which makes it unusually simple to deploy. It works on any timeframe, but because it depends on volume it is most reliable on daily and weekly charts of liquid instruments where volume data is clean and meaningful. On intraday charts it is still usable for divergence, though thin volume in individual bars makes it noisier. The absence of settings means the only real choice is the timeframe and the instrument; the tool itself is the same everywhere. For a stable divergence read most traders favor the daily chart, where accumulation and distribution play out over many sessions.
When and where to use it
The A/D Line is at its best confirming trends and hunting divergences on volume-bearing instruments — stocks, ETFs and futures — where reported volume genuinely reflects participation. It is less meaningful on spot forex, which has no centralized volume, so there tick volume is a rough proxy at best. Use it in a trending market to confirm that the trend has backing and near suspected tops and bottoms to check whether flow agrees with price. It is not a timing trigger on its own; treat it as a background gauge of conviction. Avoid leaning on it in gap-heavy names, where its blind spot distorts the reading.
Strategies that use it
The classic strategy is divergence trading: in an uptrend that has run a long way, a bearish divergence — price higher, line lower — is a cue to tighten stops or prepare for a reversal, and the bullish divergence at a downtrend's end is an accumulation signal to watch for a base. A second strategy is trend confirmation for breakouts: only take a price breakout to new highs if the line is also making new highs, since a breakout without money-flow support is prone to failure. A third approach uses the Chaikin Oscillator — the difference of a 3-period and 10-period EMA of the line — to convert the line's slope changes into concrete crossover triggers, buying when the oscillator crosses above zero after a bullish price setup. In every case the A/D Line supplies the flow context and price structure supplies the entry.
Combining it with other indicators
The A/D Line pairs naturally with price-based trend and momentum tools that it can confirm or contradict — moving averages, trendlines and RSI. RSI divergence and A/D divergence appearing together at the same price high is a far stronger reversal warning than either alone. On-Balance Volume is a useful companion because it measures flow a different way — whole-bar volume by close-to-close direction — so agreement between OBV and the A/D Line cross-validates the flow read, while disagreement is a flag to be cautious. Chaikin Money Flow, a bounded oscillator version of the same idea, lets you quantify whether recent flow is strongly positive or negative rather than just reading a slope. Support-and-resistance analysis rounds it out, since accumulation showing up as price tests a key floor is a classic bottoming tell.
Where it fails
The signature flaw is that the Money Flow Multiplier looks only inside each bar, from its own high to its own low, and completely ignores the gap between one bar's close and the next bar's open. A stock that gaps down sharply overnight but then closes near the high of the day's range will register as accumulation, even though holders who bought the prior close are underwater — a genuinely misleading result in gap-prone names. Bars with very small high-to-low ranges produce unstable multipliers, since a tiny denominator swings the result. Because it is cumulative, one abnormal volume day can shift the line's level, so reading absolute levels is meaningless. The defenses are to read shape rather than level, to be wary in gap-heavy stocks, and to confirm divergences with a second flow tool like OBV.
A worked example
Consider a stock that rallies from $40 to $50 over two months, making a series of higher highs that look strong on the price chart. A trader watching the A/D Line notices that while price pushed from a $48 high to a fresh $50 high, the line failed to exceed its earlier peak and instead drifted lower — the closes on the final push were landing in the middle of each bar's range on unremarkable volume. This bearish divergence warns that the new price high is not backed by accumulation. The trader tightens stops and, when price then breaks its short-term uptrend line near $49, exits the long or takes a small short. Price subsequently falls back to $44, and the divergence — flow quietly leaving while price made one last high — is vindicated as the early clue.