Key indicators: RSI, MACD & Bollinger Bands

Indicators are mathematical formulas applied to price (and sometimes volume) that summarise an aspect of market behaviour into an easy-to-read line or histogram. They do not contain secret information; they are derived entirely from the same prices you can see on the chart. Their value is in organising that information — highlighting momentum, volatility or trend — so you can make decisions faster and more consistently.

The most common mistake is stacking five indicators on a chart and waiting for them all to agree. Because many are built from the same data, they tend to say the same thing, creating an illusion of confirmation. Two or three complementary tools, each measuring something different, are far more useful than a crowded screen.

The Relative Strength Index (RSI) is a momentum oscillator that moves between 0 and 100, comparing the size of recent gains to recent losses. Readings above 70 are traditionally called overbought and below 30 oversold. Beginners often misread this as a sell-above-70, buy-below-30 signal, but in a strong trend RSI can stay overbought for a long time while price keeps climbing.

RSI's real power is divergence. If price makes a higher high but RSI makes a lower high, momentum is fading even as price rises — a warning that the move may be running out of steam. Bullish divergence is the mirror image at a low. Divergence does not guarantee a reversal, but it flags when a trend's engine is weakening.

The Moving Average Convergence Divergence (MACD) is built from two moving averages and a signal line, plotted with a histogram showing the distance between them. When the MACD line crosses above its signal line, momentum is turning up; a cross below suggests it is turning down. The histogram growing or shrinking shows momentum accelerating or decelerating.

MACD is most reliable when its signal agrees with the broader trend — a bullish crossover during an established uptrend is more trustworthy than one against it. Like RSI, it can also diverge from price, hinting that a trend is tiring before price confirms it.

Bollinger Bands plot a moving average with an upper and lower band set a number of standard deviations away. Because standard deviation is a measure of volatility, the bands widen when the market is volatile and contract when it is calm. A long, narrow 'squeeze' often precedes a strong directional move as energy builds and is then released.

Price tends to spend most of its time inside the bands, so tags of the outer band can mark stretched conditions — but in a trend, price can 'ride the band' for an extended run. Used well, Bollinger Bands tell you how stretched or compressed the market is, complementing the momentum picture from RSI and MACD.

A clean, complementary setup might pair one trend tool, one momentum tool and one volatility tool — for example a 50 EMA for direction, RSI for momentum and Bollinger Bands for stretch. You take a trade only when they tell a consistent story: price above the EMA, RSI turning up from a pullback, and price bouncing off the lower band in an uptrend. When the tools disagree, that disagreement is itself information — usually a signal to wait.