Wednesday December 17, 2025 Stocks That Had Their Relative Strength Index (RSI) Cross Below 50 Today $CAT $GH $GOOG $GOOGL $CSCO $APG $DHR $SGI $AMKR $ASX $GFS $LRCX $MUFG $IWM

What Is RSI Indicator?

The Relative Strength Index (RSI) is a momentum oscillator developed by J. Welles Wilder Jr. and first introduced in 1978. Displayed as a line chart directly below a price chart, the RSI quantifies the speed and magnitude of recent price changes on a 0-to-100 scale The default calculation period is 14 trading periods, usually days. It divides the average gain over those periods by the average loss to produce a value called Relative Strength (RS). The RSI is then computed as: RSI = 100 – (100 ÷ (1 + RS)) A reading above 70 is traditionally viewed as overbought, suggesting a possible price reversal or pullback. Conversely, a reading below 30 is considered oversold, indicating that prices may soon rebound. Values near 50 are generally seen as a neutral or balanced state. Traders use RSI to identify divergences - when price movement and RSI diverge in direction - which can signal weakening momentum and potential trend reversals. A bullish divergence (price makes lower lows while RSI makes higher lows) can hint at a coming rally; a bearish divergence (price makes higher highs but RSI makes lower highs) may warn of a downturn. Although RSI is simple and widely built into most charting platforms, it can produce false signals, especially during strong, sustained trends where RSI can remain overbought or oversold for extended periods. To reduce risk, traders often combine RSI with other indicators like MACD, moving averages, or trend lines.