Trend strengthLagging trend-direction and strength systemDMI

Directional Movement Index DMI

The +DI and −DI lines that reveal which side — buyers or sellers — controls the trend.

Quick answer: The Directional Movement Index is a two-line system of +DI and −DI that shows whether upward or downward movement dominates, giving trend direction, and is usually plotted with ADX, which grades the trend's strength.

In simple words

The DMI is Wilder's directional system. It plots two lines: +DI, which measures how strong the upward movement is, and −DI, which measures the downward movement. When +DI is above −DI, buyers are in control; when −DI is above +DI, sellers are. A crossover of the two lines flags a change in who is winning. The DMI is almost always shown together with ADX, which turns the same data into a single strength reading, so the pair tells you both the direction and the force of a trend.

Directional Movement Index — visual

How Directional Movement Index looks on a chart

The +DI (green) and −DI (red) lines show directional dominance: +DI above −DI is bullish control, −DI above +DI bearish. ADX, usually plotted with them, measures the strength of that dominance.

Professional explanation

How +DI and −DI are built

Each bar has a directional movement. If today's high extends above yesterday's high more than today's low drops below yesterday's low, the bar has positive directional movement (+DM); the reverse gives negative (−DM). Wilder smooths +DM and −DM over 14 periods and divides each by the smoothed True Range to get +DI and −DI as percentages. So +DI is the share of range attributable to up-moves, −DI the share from down-moves.

Crossovers as directional signals

The core DMI signal is the crossover. When +DI crosses above −DI, upward movement has overtaken downward — a bullish directional shift. When −DI crosses above +DI, the opposite. Wilder's own rule was to buy on a +DI cross using the signal bar's high as the trigger and stop. These crossovers are cleaner in trending markets and noisy in ranges, which is why ADX is used to gate them.

The spread between the lines

The distance between +DI and −DI matters as much as the cross. A wide and widening spread means one side is decisively in control — a strong, clean trend. A narrow spread with the lines weaving around each other means the market is directionless. This spread is exactly what ADX distils into a single number, which is why the DMI and ADX are read together.

Why DMI needs ADX

The DI lines answer 'which way?' but not 'how strongly?'. In a tight range +DI and −DI cross back and forth constantly, generating false directional signals. ADX solves this: only when ADX confirms a strong trend (above 20–25) are the DI crossovers worth acting on. Direction without strength is a recipe for whipsaws, so the two halves of Wilder's system are designed to be used as one.

Formula

Directional Movement Index formula

+DI = 100 × Smoothed(+DM) / ATR; −DI = 100 × Smoothed(−DM) / ATR

+DM and −DM are the directional movements per bar, smoothed with Wilder's averaging over N (default 14), and divided by the Average True Range. ADX is derived from the difference between +DI and −DI.

+DM — Positive directional movement — the excess of today's high over yesterday's high, when it exceeds the downward move
−DM — Negative directional movement — the excess of yesterday's low over today's low, when it exceeds the upward move
ATR — Average True Range — Wilder-smoothed True Range, used to normalise +DM and −DM
N — Look-back period, default 14 bars

How it is calculated

For each bar, compute the up-move (today's high − yesterday's high) and the down-move (yesterday's low − today's low).
Assign +DM to the larger up-move if it is positive and exceeds the down-move; assign −DM to the larger down-move in the opposite case; otherwise both are zero.
Smooth +DM, −DM and True Range with Wilder's averaging over N periods.
Compute +DI = 100 × smoothed +DM / smoothed TR, and −DI = 100 × smoothed −DM / smoothed TR.
Read +DI above −DI as bullish control and −DI above +DI as bearish; watch for crossovers and the spread, ideally filtered by ADX.

Interpretation & signals

Traders read the DMI for direction: +DI above −DI means buyers dominate, −DI above +DI means sellers do. Crossovers flag directional shifts, the spread shows conviction, and ADX (its companion) confirms whether the shift is strong enough to trade.

Buy / bullish signals

+DI crosses above −DI, signalling upward movement has taken control.
+DI crosses above −DI while ADX is above 20–25, confirming a strong bullish shift.
The +DI/−DI spread widens with +DI on top, showing the uptrend is gaining conviction.
In an uptrend, −DI dips and +DI holds above it after a pullback (trend continuation).

Sell / bearish signals

−DI crosses above +DI, signalling downward movement has taken control.
−DI crosses above +DI while ADX is above 20–25, confirming a strong bearish shift.
The spread widens with −DI on top, showing the downtrend is strengthening.
In a downtrend, +DI fails to reclaim −DI after a bounce (trend continuation).

False signals to beware

In a range, +DI and −DI cross back and forth repeatedly, producing whipsaw signals — the reason ADX gating is essential.
Crossovers can occur well after the move has begun because the DI lines are smoothed.
A crossover with a very narrow spread and low ADX rarely holds.

Settings, timeframe & conditions

Best settings

14 periods (Wilder default), filtered by ADX above 20–25

Avoid

Trading every DI crossover regardless of ADX or trend context

Works best in

Trending markets with a clear directional winner

Struggles in

Tight ranges where the DI lines tangle

Advantages & limitations

Advantages

Gives an objective read on which side — buyers or sellers — controls the market.
The spread between the lines shows the conviction behind a trend.
Pairs seamlessly with ADX for a complete direction-plus-strength system.
Crossovers provide clear, rule-based entry and exit points in trends.

Limitations & disadvantages

DI crossovers whipsaw badly in ranging markets without an ADX filter.
Lags because the DI lines are Wilder-smoothed.
Two lines plus ADX can look cluttered to beginners.
Direction alone is unreliable — it must be combined with strength.

Combining Directional Movement Index with other indicators

Average Directional Index — The DI lines give direction and ADX grades strength; take DI crossovers only when ADX confirms a strong trend — this is Wilder's intended combination.
Average True Range — ATR, which underpins the DI calculation, also sizes stops for DMI-based trend entries.
Moving Average — A moving-average trend filter keeps you taking only the DI crossovers aligned with the larger trend, cutting counter-trend whipsaws.

Practical examples (Nifty & Bank Nifty)

NIFTY example

Nifty has been falling and −DI is above +DI. As Nifty bases and turns up, +DI climbs and crosses above −DI while ADX is at 22 and rising through 25. That +DI crossover, confirmed by a rising ADX above 25, is the DMI's textbook bullish signal — direction (the cross) plus strength (ADX) together tell a trend-follower the up-move is real, not a range bounce.

BANKNIFTY example

Bank Nifty is stuck in a tight consolidation and its +DI and −DI lines cross each other four times in a week while ADX languishes at 14. A trader who acts on each DI crossover is whipsawed repeatedly. The correct read is that ADX below 20 invalidates the DI signals — the lines are tangled because there is no trend, so the DMI is saying 'stand aside' until ADX confirms a directional winner.

Common mistakes

Trading DI crossovers without checking ADX — the classic whipsaw trap in ranges.
Reading +DI/−DI as overbought/oversold levels; they show direction, not extremes.
Ignoring the spread between the lines, which signals conviction.
Expecting the crossover to be early — the DI lines are smoothed and lag.

Professional usage

Professionals treat the DMI and ADX as a single instrument. They use the DI crossover and the DI spread to identify which side controls the market and how decisively, but they only act when ADX confirms the trend is strong enough. In systematic trend strategies a +DI/−DI cross is often one directional input combined with an ADX strength gate and a higher-timeframe filter, never a standalone trigger — because the whole point of Wilder's system is that direction and strength must agree.

Key takeaway

The DMI is Wilder's directional compass: +DI above −DI means buyers control the trend, −DI above +DI means sellers do, and the crossover flags the handover. But direction is only half the story — pair it with ADX so you act on crossovers only when the trend is genuinely strong, or the DI lines will whipsaw you in every range.

Frequently asked questions

What is the DMI indicator?

The Directional Movement Index is a system created by J. Welles Wilder in 1978 that plots +DI and −DI lines to show whether upward or downward movement dominates. It reveals trend direction and is usually shown with ADX, which measures the trend's strength.

What is the difference between +DI and −DI?

+DI measures the strength of upward price movement and −DI the strength of downward movement. When +DI is above −DI, buyers control the trend; when −DI is above +DI, sellers do. Their crossover signals a change in control.

How is DMI different from ADX?

They are two parts of the same system. The DMI is the +DI and −DI lines that give direction; ADX is a single line derived from them that grades strength. DMI says which way, ADX says how strongly.

What is a DMI crossover?

A DMI crossover is when +DI and −DI cross. +DI crossing above −DI is a bullish directional signal; −DI crossing above +DI is bearish. Crossovers are most reliable when ADX confirms a strong trend.

What are the best DMI settings?

The standard is 14 periods, following Wilder's original design. The DI lines are then usually filtered by requiring ADX above 20–25 before acting on a crossover, to avoid whipsaws in ranging markets.

Is DMI a leading or lagging indicator?

DMI is a lagging indicator because the +DI and −DI lines are smoothed with Wilder's averaging. Crossovers can occur after a move has begun, so they are best used with confirmation rather than as early signals.

Why does DMI whipsaw?

In ranging markets +DI and −DI stay close together and cross back and forth repeatedly, generating false signals. This is why the DMI should be filtered by ADX — only crossovers occurring while ADX is above 20–25 are considered reliable.

How do you trade with the DMI?

The common approach is to go long when +DI crosses above −DI and short when −DI crosses above +DI, but only when ADX confirms a strong trend. The spread between the DI lines shows how much conviction is behind the move.

What does the DI spread tell you?

The distance between +DI and −DI shows the conviction behind a trend. A wide, widening spread means one side decisively controls the market; a narrow spread with the lines weaving means the market is directionless.

Can DMI be used for Nifty and Bank Nifty?

Yes. The DMI works on any liquid instrument. On Nifty and Bank Nifty it is valuable for reading directional control, but because both alternate between trends and ranges, the ADX filter is important to avoid whipsaws.

Is DMI the same as the ADX indicator?

Not exactly — they are companions. The DMI refers to the +DI and −DI directional lines, while ADX is the strength line built from them. Many charting platforms plot all three together and label the whole thing DMI or ADX interchangeably.

Does DMI work in a range?

Poorly on its own. In a range the DI lines cross repeatedly and produce false signals. The DMI is designed for trending markets, which is why it is paired with ADX to filter out the low-strength, range-bound crossovers.

Voice search & related questions

Natural-language questions people ask about Directional Movement Index.

What is DMI in simple words?

DMI plots two lines: a plus line for upward strength and a minus line for downward strength. When the plus line is on top, buyers are winning; when the minus line is on top, sellers are winning.

Is a DI crossover a buy signal?

A +DI crossing above −DI can be a buy signal, but it is only reliable when ADX confirms a strong trend. In a range the DI lines cross constantly and those signals fail.

What is the difference between DMI and ADX?

DMI's plus and minus lines tell you the direction of the trend, while ADX tells you how strong that trend is. You use them together — direction from DMI, strength from ADX.

How do I use DMI for day trading?

On intraday charts, watch for the DI lines to cross while ADX is rising above 20–25, which confirms a real intraday trend, and avoid acting when the lines are tangled and ADX is low.

Which line is bullish on DMI?

The +DI line is the bullish one. When +DI is above −DI, upward movement dominates and the trend bias is up; when −DI is above +DI, the bias is down.

Sources & references

Last reviewed 8 July 2026. Educational content only — not investment advice.