Key Takeaway: RSI measures momentum, not absolute direction. "Overbought" at 70+ doesn't mean sell — in strong uptrends, RSI can stay above 70 for weeks. The real signals are RSI divergences (price makes new highs while RSI doesn't), RSI centerline crosses (50 level), and RSI breakouts above/below key levels during consolidation.
Relative Strength Index (RSI) is a momentum oscillator developed by J. Welles Wilder. It measures the speed and magnitude of price changes over a lookback period (default: 14 periods).
The formula in plain English: RSI compares the average of up-days to down-days over the past 14 candles. If the stock went up 10 of the last 14 days and the average gain was large, RSI will be high. If the stock fell most of the time, RSI will be low.
Output range: 0–100
The most common RSI mistake: seeing RSI at 75 and selling because it's "overbought."
In a strong uptrend, RSI routinely stays above 70 for extended periods. NVDA during its AI-driven rally of 2023–2024 spent weeks with RSI above 70. Selling every time RSI crossed 70 would have meant repeatedly fading one of the strongest trends of the decade.
The correct interpretation: RSI above 70 means strong momentum. In a trending market, strong momentum continues. Use RSI overbought/oversold readings as context, not as entry/exit signals in isolation.
Overbought is only actionable when it occurs with a divergence, at a major resistance level, or after an exhaustion move.
The most reliable RSI signal is divergence — when price and RSI disagree.
Bearish divergence: Price makes a higher high, but RSI makes a lower high. The new price high was achieved with less momentum than the previous high. A warning that the trend is weakening.
Bullish divergence: Price makes a lower low, but RSI makes a higher low. The new price low was reached with less bearish momentum. A potential reversal signal.
Important caveat: Divergences are early warning signals, not entry triggers. Price can diverge for several candles before actually reversing. Always wait for price confirmation — a candlestick reversal pattern, a break of a trendline, or a clear failure at resistance — before acting on a divergence.
The RSI 50 level is underused by retail traders. It's the line between bullish and bearish momentum:
In strongly trending stocks, RSI typically stays above 50 during the uptrend and below 50 during corrections. A pullback that holds RSI above 50 is often a buying opportunity within an uptrend. A bounce that fails to get RSI back above 50 often signals continued weakness.
Trending markets (RSI range 40–90 for uptrends): In a strong uptrend, "oversold" for that trend might be RSI at 40, not 30. Adjust your reference points to the actual range RSI has been trading in.
Ranging markets (RSI 30–70 works well): In choppy, sideways action, the classic 30/70 levels function well because the stock is genuinely oscillating.
Adjusting the period:
RSI helps with timing and strike selection:
Entry timing: When a stock you're bullish on pulls back and RSI drops to 40–50 without breaking the uptrend, that's a potential swing entry with options. You're buying into controlled weakness, not chasing.
Exit confirmation: If a stock you hold calls on sees RSI diverge bearishly at a major resistance level, that's a signal to take partial profits or tighten your stop.
Earnings context: RSI overbought into earnings (RSI 75+) combined with an extreme IV Rank is a particularly dangerous setup for long call buyers. Both momentum and volatility are stretched.
In Thetaview technical analysis articles, RSI signals are called out when they provide meaningful context — specifically divergences, breaks of the 50 level, and overbought/oversold readings at key price levels. A standalone RSI reading without price context is mentioned for reference only, not as an actionable signal.