Lesson 48 of 69

RSI, MACD and Bollinger Bands

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These three cover the questions do not answer: how strong is the current move, is shifting, and is the market quiet or wild right now. Learn what each one measures, then use at most one or two — stacking five indicators just gives you the same opinion five times.

RSI —

RSI compares the size of recent up closes to the size of recent down closes over a lookback period (14 by default) and turns that ratio into a number between 0 and 100. High means buyers have dominated recently; low means sellers have.

RSI overbought and oversoldThe RSI line rises into the shaded band above 70 and falls into the shaded band below 30 before turning back.OVERBOUGHT — above 70OVERSOLD — below 30RSI (14)
  • Above 70 is called , below 30 . That describes speed, not a — in a strong RSI can sit above 70 for weeks.
  • The 50 line is an underrated trend filter: above 50 favours buys, below 50 favours sells.
  • is the highest-value use: price makes a higher high but RSI makes a lower high, meaning the new high came with less force. Treat it as a warning, then wait for a to confirm.

— Moving Average Convergence Divergence

MACD is built from two EMAs. The MACD line is the difference between a fast and a slow , the signal line is a short average of the MACD line, and the histogram is the between the two. It measures whether momentum is expanding or fading.

MACD line, signal line and histogramThe MACD line crosses above the signal line as histogram bars flip from red below the zero line to green above it.BULLISH CROSSOVERMACD lineSignal lineHistogram = distance between them
  • MACD line crossing above the signal line points to strengthening momentum; crossing below points to .
  • The zero line matters: crossovers above zero in an are far more reliable than crossovers against the bigger trend.
  • Shrinking histogram bars mean the current move is running out of steam even while price still ticks higher — a good reason to tighten a stop, not to reverse.
  • Like RSI, MACD can diverge from price, and it is at its worst in markets.

Bollinger Bands plot a 20-period moving average with an upper and lower band placed a couple of standard deviations away. When the market is quiet the bands together; when it is volatile they expand.

Bollinger Bands squeeze and expansionUpper and lower bands narrow around a flat middle average, then widen sharply as price breaks out upward.SQUEEZE — low volatilityEXPANSION — breakoutMiddle band = 20 SMA
  • A squeeze means volatility is compressed and a larger move is often building — it tells you something is coming, not which direction.
  • In a range, touches of the outer bands mark stretched prices where a reversion to the middle band is likely.
  • In a strong trend, price can ride the upper or lower band for a long time. Selling every upper-band touch in an uptrend is a classic beginner loss.
  • The middle band (the 20 ) often acts as dynamic and during trends.
IndicatorMeasuresBest used for
Moving averagesDirection and average priceTrend filter, pullback areas
RSIMomentum strength (0-100)Stretched conditions, divergence
MACDMomentum expanding or fadingTrend shifts, exit timing
Bollinger BandsVolatility around an averageSqueezes, range extremes

How to add these without ruining your chart

Start with a clean chart and price action only. Add one indicator, trade it for a month, and keep it only if it changed decisions for the better. Two indicators that measure different things (a moving average plus RSI) beat four that all measure momentum.

The rule that outlives every indicator

No indicator tells you where to place your stop or how big your position should be — and those two decisions determine whether you survive. Price action and risk management first; indicators are the finishing touch.

Key takeaways

  • RSI measures the speed and size of recent moves on a 0-100 scale.
  • Overbought can stay overbought in a strong trend — it is not a sell signal.
  • MACD compares two moving averages to show momentum shifts.
  • Bollinger Bands show volatility, widening in fast markets and contracting in quiet ones.

Knowledge check

3 quick questions — your best score is saved to your progress.

  1. 1. What does RSI measure?

  2. 2. In a strong trend, an 'overbought' RSI usually means…

  3. 3. What do Bollinger Bands show?

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