Trading Indicators Explained: RSI, MACD, EMA, Bollinger Bands & ATR

Trading indicators are mathematical calculations applied to price data. They help you identify trends, momentum, volatility, and potential reversal points.

But here's the catch: indicators don't predict the future. They describe the present. The edge comes from combining the right indicators with proper risk management and letting a trading bot execute without hesitation.

Here's every indicator you need to know — with Pine Script code you can use on PineForge today.

Trend Indicators

Moving Averages: SMA vs EMA

The foundation of technical analysis.

SMA (Simple Moving Average): Equal weight to all periods. Slower, smoother, less reactive to sudden moves.

EMA (Exponential Moving Average): More weight on recent prices. Faster, more responsive. Preferred for algo trading.

How to use them:

fast = ta.ema(close, 9)

slow = ta.ema(close, 21)

bullish = ta.crossover(fast, slow)

bearish = ta.crossunder(fast, slow)

MACD: Momentum Meets Trend

The MACD reveals momentum shifts by measuring the relationship between two EMAs.

Components:

Trading signal: Buy when MACD crosses above signal. Sell when it crosses below.

[macdLine, signalLine, hist] = ta.macd(close, 12, 26, 9)

buy_signal = ta.crossover(macdLine, signalLine)

sell_signal = ta.crossunder(macdLine, signalLine)

Momentum Indicators

RSI: Overbought and Oversold

The Relative Strength Index measures the speed and magnitude of price changes on a scale of 0 to 100.

Key levels:

rsi = ta.rsi(close, 14)

oversold = rsi < 30

overbought = rsi > 70

RSI works best as a filter, not a standalone signal. Combine it with a trend indicator for higher-probability trades. Example: only buy RSI oversold bounces when price is above the 50 EMA.

Volatility Indicators

Bollinger Bands

Bollinger Bands measure volatility using standard deviations from a moving average.

Components:

Trading signals:

[mid, upper, lower] = ta.bb(close, 20, 2)

at_lower = close <= lower

at_upper = close >= upper

squeeze = (upper - lower) / mid < 0.02 // narrow bands

ATR: The Volatility Ruler

The Average True Range measures how much price moves per bar. It doesn't indicate direction — just magnitude.

Why ATR matters for algo trading: It's the best way to set dynamic stop-losses that adapt to market conditions.

atr = ta.atr(14)

dynamic_stop = close - 2 * atr // widens in volatile markets

In a calm market, ATR is small → tight stop. In a volatile market, ATR is large → wider stop. This prevents getting stopped out by normal noise while still protecting against real reversals.

How Should You Combine Trading Indicators?

The best strategies combine indicators from different categories:

Avoid: combining indicators from the same category (e.g., RSI + Stochastic). They measure similar things and don't add real information.

From Indicators to Automated Strategy

Every indicator on this page is available in Pine Script and fully supported by PineForge's backtesting and live trading engine.

The workflow:

Test indicator strategies on PineForge — backtest any combination in seconds.

fast = ta.ema(close, 9)
slow = ta.ema(close, 21)
bullish = ta.crossover(fast, slow)
bearish = ta.crossunder(fast, slow)

[macdLine, signalLine, hist] = ta.macd(close, 12, 26, 9)
buy_signal = ta.crossover(macdLine, signalLine)
sell_signal = ta.crossunder(macdLine, signalLine)

rsi = ta.rsi(close, 14)
oversold = rsi < 30
overbought = rsi > 70

[mid, upper, lower] = ta.bb(close, 20, 2)
at_lower = close <= lower
at_upper = close >= upper
squeeze = (upper - lower) / mid < 0.02  // narrow bands

atr = ta.atr(14)
dynamic_stop = close - 2 * atr  // widens in volatile markets