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Technical Indicators

3.3 Trend-Following Indicators

Master MACD and ADX — the two most useful trend-following indicators. Understand when they help and when they fail.

Layer 3: Technical Indicators — Chapter 3 Goal: Master MACD and ADX — the two most useful trend-following indicators. Understand when they help and when they fail.

The Core Idea

While moving averages tell you about price relative to its average, trend-following indicators measure the strength and direction of the underlying trend itself. They help answer: "Is this stock trending hard, or just drifting?"

The two indicators worth knowing here: MACD (Moving Average Convergence Divergence) and ADX (Average Directional Index).

MACD: Moving Average Convergence Divergence

Developed by Gerald Appel in the 1970s. One of the most popular indicators ever.

What It Is

MACD is literally just the difference between two EMAs. That's it. Despite its mysterious-sounding name, it's mathematically simple.

Formula

MACD Line = 12-period EMA - 26-period EMA
Signal Line = 9-period EMA of MACD Line
Histogram = MACD Line - Signal Line

Three Components

  1. MACD Line (blue line typically) — the actual difference between fast and slow EMAs
  2. Signal Line (orange/red) — a smoothing of the MACD line
  3. Histogram (bars above/below zero) — the difference between MACD and Signal

Why These Periods?

  • 12 and 26: roughly 2 weeks and 5 weeks of trading days
  • 9: 2 weeks signal smoothing
  • Default since the 1970s
  • Don't change them unless you have a good reason

How to Read MACD

Zero Line

  • MACD > 0 → fast EMA > slow EMA → bullish bias
  • MACD < 0 → fast EMA < slow EMA → bearish bias
  • The further from zero, the stronger the trend

Signal Line Crossovers

  • Bullish crossover: MACD line crosses ABOVE Signal line
  • Bearish crossover: MACD line crosses BELOW Signal line
  • Acts as a trade trigger (with limits)

Histogram

  • Tells you the distance between MACD and Signal
  • Growing histogram = momentum increasing
  • Shrinking histogram = momentum decreasing (often precedes crossovers)
  • Histogram color often flips before MACD itself crosses

Zero Line Crossovers

  • More significant than signal line crossovers
  • MACD crossing above zero = major trend shift up
  • MACD crossing below zero = major trend shift down

MACD Divergence

Like RSI, MACD shows divergence. Often more reliable than RSI divergence on longer timeframes.

Bullish Divergence

  • Price makes lower low
  • MACD makes higher low
  • Momentum is improving even though price is dropping

Bearish Divergence

  • Price makes higher high
  • MACD makes lower high
  • Momentum is fading even though price is rising

Best Use

  • Higher timeframes (daily, weekly)
  • At major support/resistance levels
  • Combined with reversal candles

MACD Limitations

1. Lagging Indicator

By definition, MACD uses past prices. Crossovers happen after the move has started.

2. False Signals in Ranges

In sideways markets, MACD generates constant crossovers, mostly noise.

3. No "Strength" Reading

MACD tells direction but not magnitude. A weak trend and a strong trend can both have similar MACD readings.

This is where ADX comes in.

ADX: Average Directional Index

Also developed by J. Welles Wilder. Measures the strength of a trend, regardless of direction.

What It Measures

The strength of price's directional movement, on a scale of 0-100.

Key Concept

ADX answers: "Is this stock trending hard, or just drifting?"

It does NOT tell you direction (up or down). It only tells strength.

Reading

ADX Value Interpretation
0 - 20 Weak or no trend (ranging market)
20 - 25 Possible trend developing
25 - 50 Strong trend
50 - 75 Very strong trend
75 - 100 Extreme trend (rare, often near exhaustion)

The Big Rule

Trend-following strategies work best when ADX > 25.

Below 25 → market is ranging → mean-reversion strategies work better.

DI+ and DI- (The Other Pieces)

ADX comes with two companion lines:

DI+ (Positive Directional Indicator)

Measures upward price movement.

DI- (Negative Directional Indicator)

Measures downward price movement.

Interpretation

  • DI+ above DI- = uptrend (direction)
  • DI- above DI+ = downtrend (direction)
  • ADX = strength of either trend

Practical Use

  • ADX > 25 AND DI+ above DI- = strong uptrend → consider longs
  • ADX > 25 AND DI- above DI+ = strong downtrend → consider shorts
  • ADX < 20 = no trend → range trading or stay out

How to Use ADX in Practice

Filter Your Trades

Only take trend-following setups when ADX > 25 on the daily chart.

Why? Because trend setups in ranging markets have very low win rates. ADX filters those out.

Adjust Strategy by Regime

  • High ADX: trade trend continuation, ride moving averages
  • Low ADX: trade range edges, mean reversion
  • Rising ADX from low: trend is forming → enter early
  • Falling ADX from high: trend is exhausting → take profits

A Simple Rule

"Don't trade breakouts when ADX is below 20."

Using MACD and ADX Together

These complement each other.

MACD + ADX Workflow

  1. ADX check first: Is ADX above 25?

    • Yes → trend is strong, look for setups
    • No → trend is weak, be cautious or trade range

  2. Direction check: Where's MACD?

    • Above zero with bullish crossover → long bias
    • Below zero with bearish crossover → short bias

  3. Confirmation: Does price action agree?

    • At support/resistance, with reversal candles, etc.

Example

  • ADX = 32 (strong trend)
  • MACD just crossed above signal line
  • Price bouncing off 20 EMA in uptrend
  • Bullish engulfing candle

All systems go. Strong long signal.

Common Mistakes

1. Treating MACD Crossovers as Standalone Signals

Crossovers in ranges are mostly noise. Filter with ADX.

2. Ignoring the Direction of ADX Slope

ADX rising = trend strengthening. ADX falling = trend weakening. Both matter.

3. Using MACD Without Higher Timeframe Context

Daily MACD bullish crossover is meaningless if weekly is in clear downtrend.

4. Reading ADX as Direction

ADX is direction-agnostic. High ADX could mean strong uptrend OR strong downtrend. Check DI+ and DI- (or just look at price).

5. Forgetting MACD is Just Two EMAs

If you already have MAs on your chart, MACD is somewhat redundant. Use one or the other primarily.

When These Indicators Fail

MACD Fails When:

  • Market is choppy/ranging (false crossovers)
  • After a violent reversal (lag is too costly)
  • Low-volume sessions
  • News-driven gaps (no smooth trend to track)

ADX Fails When:

  • Trend is mature but exhausted (high ADX, about to reverse)
  • During regime transitions (low ADX as new trend emerges)
  • Very short timeframes (too noisy)

A Mental Model

Think of trend-following indicators as weather instruments:

  • MACD = wind direction indicator (which way the trend blows)
  • ADX = wind speed indicator (how hard the trend blows)

You wouldn't decide what to wear based on wind direction alone. You also need speed.

A 5 mph breeze going east is comfortable. A 50 mph wind going east is dangerous.

Same with trends. Direction matters less than magnitude (and vice versa).

Practical Setup

For swing trading on daily chart:

Default Configuration

  • MACD (12, 26, 9) — standard
  • ADX (14) — standard

Don't Add More

You don't need:

  • Multiple MACDs at different periods
  • Both ADX and ATR-based trend filters
  • Multiple oscillators stacked

Two indicators in the trend-following category is plenty.

When These Indicators Are Most Useful

MACD: Best For

  • Confirming direction in trending markets
  • Spotting momentum shifts (histogram changes)
  • Divergence at major levels

ADX: Best For

  • Deciding WHEN to use trend-following strategies
  • Filtering out ranging environments
  • Recognizing trend exhaustion (high ADX falling)

Practical Takeaways

  1. MACD is just two EMAs subtracted from each other. Demystify it.

  2. MACD signals: zero line crossovers > signal line crossovers > histogram changes in importance.

  3. MACD divergence at major levels is one of the best signals.

  4. ADX measures strength, not direction. Use it to decide whether to trend-follow.

  5. ADX > 25 is the green light for trend-following strategies.

  6. MACD + ADX together gives you direction + strength.

  7. Don't trade MACD crossovers in low-ADX environments. Mostly noise.

Quick Self-Check

Before moving to 3.4, you should be able to answer:

  • How is MACD calculated?
  • What's the difference between MACD line and signal line?
  • What's the MACD histogram?
  • What does ADX measure?
  • What's the threshold for "strong trend" on ADX?
  • What's the difference between MACD's role and ADX's role?
  • Why is MACD crossovers in low-ADX markets dangerous?

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