Volume & money flowChaikin Money Flow · CMF
The Accumulation/Distribution idea condensed into a bounded oscillator that swings around zero.
Works in most conditionsEngine-computed on a fixed sample series
What it is
Chaikin Money Flow (CMF), created by Marc Chaikin, measures the net buying and selling pressure flowing through a market over a set number of bars, usually 20 or 21 days. Its central insight is about where price closes within each bar's range: a close near the high implies buyers dominated that bar, and a close near the low implies sellers did. CMF weights that positioning by volume and sums it over the window, producing a single number that says whether accumulation (buying) or distribution (selling) has been in control. It answers a question raw price cannot: is the crowd quietly buying into strength or selling into it? The tool oscillates around a zero line, with positive readings signalling accumulation and negative readings distribution.
How it is calculated
Each bar first gets a Money Flow Multiplier equal to ((Close - Low) - (High - Close)) / (High - Low), which runs from +1 when the close equals the high to -1 when it equals the low. That multiplier is applied to the bar's volume to get Money Flow Volume = Multiplier x Volume, the volume-weighted buying or selling pressure for the bar. CMF then sums the Money Flow Volume over the lookback (20 or 21 bars by default) and divides by the sum of volume over the same window, so CMF = Sum of Money Flow Volume / Sum of Volume. Dividing by total volume normalises the result to roughly the -1 to +1 range, though in practice it rarely strays beyond about -0.5 to +0.5. Because the multiplier looks only inside each bar and ignores the gap from one close to the next open, CMF reads intrabar positioning rather than bar-to-bar change.
Reading it, step by step
The zero line is the anchor: sustained readings above zero mean buying pressure has dominated the window, and sustained readings below mean selling pressure has. Magnitude matters too, so many traders treat crossings beyond +0.05 to +0.10 as meaningful buying and below -0.05 to -0.10 as meaningful selling, reserving readings past positive or negative 0.25 for strong pressure. How long CMF holds one side of zero is as important as the reading itself: a value that stays positive for weeks confirms a healthy uptrend, while a quick dip below zero on a pullback may mean little. Divergence is a key read: if price makes a new high but CMF makes a lower high or slips under zero, buying pressure is not confirming the advance and the move is suspect. The reverse, price sinking while CMF turns up, hints at quiet accumulation beneath a falling tape.
Best timeframes and settings
The classic setting is 20 or 21 periods, matching roughly one month of trading days, and CMF is primarily a daily-chart tool for gauging accumulation and distribution in stocks and ETFs. Shortening the window toward 10 makes it more responsive to recent flow but noisier and quicker to cross zero, while lengthening toward 40 or more smooths it into a slower, more strategic read of positioning. Because the calculation leans on volume, it works best on instruments with reliable, meaningful volume such as cash equities and ETFs, and it is weaker on spot forex where centralised volume does not exist. On intraday charts it can be applied but is noisier and more sensitive to session open and close distortions. The core trade-off is familiar: a shorter window catches shifts in pressure sooner at the cost of more false zero-line crosses.
When and where to use it
Use CMF to confirm whether a price trend is backed by real buying or selling pressure, especially to validate breakouts and to hunt for divergences that warn a move is running out of participants. It is most at home on liquid stocks and ETFs on the daily timeframe, where volume is trustworthy and the accumulation-versus-distribution story is meaningful. It shines as a confirmation layer: a breakout accompanied by CMF pushing firmly above zero is more trustworthy than one where CMF stays flat or negative. Avoid relying on it in markets without true volume data, and be cautious on instruments whose volume is dominated by a few large prints that can swing the multiplier. It is a pressure gauge, not a timing trigger, so it is best paired with price-based entries rather than traded on its own.
Strategies that use it
Breakout confirmation: act on a price breakout above resistance only if CMF is simultaneously above zero, ideally rising past +0.10, and pass on breakouts where CMF is negative, treating those as unconfirmed. Zero-line bias: hold or add to longs while CMF stays positive and step aside or tighten stops once it crosses and holds below zero, using the crossover as a regime flag rather than a precise entry. Divergence reversal: when price prints a higher high but CMF prints a lower high, prepare for a pullback and look for a price trigger such as a failed retest or a bearish candle to act on, with the opposite for bullish divergence at lows. Across these, CMF supplies the pressure read while price structure supplies the exact entry and stop.
Combining it with other indicators
CMF pairs naturally with price-based support and resistance, since a CMF confirmation at a clean breakout level is far stronger than either alone. Because CMF and the raw Accumulation/Distribution Line share the same money-flow foundation, traders often add a trend tool like a moving average to separate genuine trend from noise around the zero line. On-Balance Volume or the Chaikin Oscillator can corroborate a CMF divergence, giving two independent volume reads before acting. A momentum oscillator such as RSI adds an overbought or oversold dimension CMF lacks, so a bearish CMF divergence that lines up with an overbought RSI is a stronger warning. The recurring theme is to use CMF as the volume-pressure vote in a small committee of confirming tools rather than as a standalone signal.
Where it fails
CMF's biggest blind spot is gaps: because the multiplier looks only inside each bar's high-low range, a market that gaps sharply higher and then closes mid-range can print a neutral or negative CMF even though real buying drove the gap, understating the pressure. Thinly traded names with a few dominant volume prints can whipsaw the reading, and instruments without true volume data render it meaningless. It is also prone to shallow, meaningless zero-line crosses during quiet consolidations, which tempts overtrading. Like all divergence tools it can flag a warning that price ignores for a long time, so a divergence is a caution, not a countdown. The fixes are to demand price confirmation, to weight sustained readings over brief crosses, and to use it only where volume is real and well distributed.
A worked example
Suppose over three bars a stock trades as follows. Bar one: high 12, low 10, close 11.5, volume 1,000, so the multiplier is ((11.5 - 10) - (12 - 11.5)) / (12 - 10) = (1.5 - 0.5) / 2 = 0.5 and Money Flow Volume is +500. Bar two: high 13, low 11, close 11.2, volume 1,500, so the multiplier is (0.2 - 1.8) / 2 = -0.8 and Money Flow Volume is -1,200. Bar three: high 12.5, low 11.5, close 12.4, volume 1,200, so the multiplier is (0.9 - 0.1) / 1 = 0.8 and Money Flow Volume is +960. Summing money flow gives 500 - 1,200 + 960 = 260, and total volume is 1,000 + 1,500 + 1,200 = 3,700, so CMF = 260 / 3,700 which is about +0.07. That modestly positive reading says buyers narrowly held the upper hand across the three bars despite heavy selling in bar two, and it sits just above the +0.05 threshold many traders use to flag genuine accumulation.