RSI gets taught wrong almost everywhere you look. Most explanations say the same thing: "above 70 is overbought, below 30 is oversold, sell when it crosses down from 70, buy when it crosses up from 30." And then people trade that way and wonder why it doesn't work.
Here's what RSI actually is, how I use it in my weekly scans, and what it's really telling you.
What RSI Is Actually Measuring
RSI stands for Relative Strength Index. Developed by J. Welles Wilder in 1978. The math: it compares the average gain on up days to the average loss on down days over a lookback period (default 14 periods).
The output is a number between 0 and 100. That number tells you the momentum of price movement — not the direction of price, but how strong the move is.
This distinction matters. A stock can be at RSI 80 and keep climbing for weeks. A stock can be at RSI 25 and keep dropping. The number alone doesn't tell you to buy or sell. It tells you the character of the move.
The 70/30 Rule Is Backwards for Trending Markets
Here's the thing: in a strong uptrend, RSI regularly lives between 50 and 80. It hits 70, pulls back to 55, bounces back to 75, pulls back to 60. That's a healthy bull move. If you sell every time RSI hits 70, you exit a trend early every single time.
The 70/30 lines are more useful as context than as signals.
- RSI spending a lot of time above 60? You're in a bullish trend.
- RSI struggling to get above 50? The bears are in control.
- RSI grinding between 40 and 60 for weeks? Consolidation. No edge either way.
What I Actually Look For: Divergence
The most useful thing RSI does is divergence — when price and momentum disagree.
Bearish divergence: Price makes a new high. RSI makes a lower high. Momentum is weakening even though price looks strong. This is a warning.
Bullish divergence: Price makes a new low. RSI makes a higher low. Sellers are exhausting themselves. Momentum is improving even though price looks weak.
Divergence alone isn't a trade. It's a signal to pay closer attention. I use it in combination with Fibonacci levels and harmonic pattern completions. If a stock is completing a Gartley pattern at a key Fibonacci level and showing RSI bullish divergence on the weekly, that's a confluence worth studying closely.
RSI in My Weekly Scan
When I scan 11,000+ charts every week, RSI is one of several filters. I'm not looking for "RSI above 70 = overbought." I'm looking at:
- Where RSI is relative to its own range — a stock that's had RSI between 30-50 for months and just pushed to 60 is showing something new
- Divergence on weekly charts — takes longer to develop, carries more weight
- RSI behavior at pattern completion zones — if the price target for a harmonic pattern lines up with RSI hitting oversold, that's interesting
The Number That Matters More Than 70 or 30
50. The RSI 50 line is the centerline — it separates bullish and bearish momentum. When RSI crosses above 50 from a sustained period below it, that's a potential momentum shift. When it gets rejected at 50 repeatedly from below, the downtrend is still intact.
I watch the 50 line more than the 70 or 30 lines. It's less exciting but more actionable.
Timeframe Matters More Than People Realize
RSI on a 5-minute chart is noise. RSI on a daily chart is useful. RSI on a weekly chart is meaningful. The longer the timeframe, the more weight you can put on what you're seeing.
When I share RSI analysis in my weekly research notes, it's almost always weekly chart RSI. A stock showing RSI bullish divergence on the weekly is a much bigger deal than the same divergence on a 15-minute chart.
This is educational content — my personal research notes on how I study indicators. Not financial advice. Every chart is different and there are no guarantees in market analysis.