What is RSI (Relative Strength Index)?

The Relative Strength Index (RSI) is a momentum oscillator developed by J. Welles Wilder Jr. in 1978. It measures the speed and magnitude of recent price changes on a scale from 0 to 100. The standard calculation uses 14 periods (typically 14 trading days) and compares the average gain during up periods to the average loss during down periods to produce a single number reflecting momentum strength.

The most common interpretation is that an RSI above 70 indicates an overbought condition, suggesting the stock may be due for a pullback, while an RSI below 30 indicates oversold conditions, suggesting a potential bounce or reversal. However, experienced traders know that stocks can remain overbought or oversold for extended periods during strong trends. RSI divergences, where the price makes a new high but RSI does not (or vice versa), are considered more reliable trading signals.

RSI can also be used to identify the overall trend. When RSI consistently stays above 40 and frequently touches 70-80, the stock is in an uptrend. When it consistently stays below 60 and frequently touches 20-30, the stock is in a downtrend. The midline at 50 often acts as support in uptrends and resistance in downtrends.

Traders can adjust the RSI period to match their trading style. Shorter periods (e.g., 7 or 9) make RSI more sensitive and generate more signals, which suits day traders. Longer periods (e.g., 21 or 25) smooth out noise and suit swing traders and investors. Many charting platforms allow you to overlay RSI on price charts alongside other indicators like MACD or Bollinger Bands for confirmation.

Cannabis stocks tend to exhibit higher volatility than the broader market, which has important implications for using rsi (relative strength index) as a trading tool. Standard parameter settings that work well for large-cap stocks may need adjustment for cannabis names, where daily price swings of 5-10% are not uncommon. Traders may want to use wider bands, longer periods, or more conservative signal thresholds when applying this indicator to cannabis charts.

The cannabis sector is also prone to sharp, news-driven moves triggered by regulatory announcements, earnings surprises, or industry-wide catalysts. These sudden moves can overwhelm technical signals, causing indicators like rsi (relative strength index) to give false or delayed readings. Combining technical analysis with awareness of the cannabis regulatory calendar and earnings schedule helps traders avoid being caught off guard by fundamental catalysts that override technical patterns.