The Relative Strength Index (RSI) is one of the most widely quoted numbers in technical analysis, and also one of the most widely misread. The number itself is simple: it tells you how strong recent gains have been compared to recent losses, expressed on a 0–100 scale. But “oversold at 30” is not a buy signal. Here is why.
How the calculation works
RSI looks at the last 14 candles by default. It computes the average gain on up-candles and the average loss on down-candles, then divides:
RS = average gain / average loss
RSI = 100 − (100 / (1 + RS))When gains dominate heavily, RS is large and RSI pushes toward 100. When losses dominate, RS shrinks toward zero and RSI falls toward 0. Fifty is the neutral midpoint — neither gains nor losses have a systematic edge over the window.
The oversold myth
The classic teaching is: RSI below 30 = oversold = buy. RSI above 70 = overbought = sell. This works reasonably well in ranging markets where price oscillates between support and resistance. It breaks down — often badly — in trending markets.
In a strong downtrend, RSI can sit below 30 for weeks. Each oversold reading invites buyers; each bounce gets sold. The downtrend wins. Buying every RSI-30 touch during a bear market is a reliable way to catch falling knives.
The opposite is equally true: in a strong uptrend RSI can ride above 70 for an extended run. Shorting every RSI-70 touch during a bull run is expensive.
The practical rule: RSI level alone is not a signal. RSI level in context of trend direction matters. An oversold RSI during an uptrend is a potential entry. The same reading during a downtrend is a warning to wait.
How SignalsDeck votes RSI
On the crypto dashboard, each coin’s RSI is computed on the selected timeframe (5m through 1W). The vote rule is straightforward:
- RSI below 30 → +1 (bullish — oversold dip in context)
- RSI above 70 → −1 (bearish — overbought extension)
- RSI between 30 and 70 → 0 (no strong signal)
The RSI vote is one of five inputs into the final LONG/SHORT/NEUTRAL verdict. A single oversold RSI reading in a sea of bearish indicators still produces a neutral or short verdict — the vote is normalized against the others.
RSI divergence (not in the vote, but worth knowing)
RSI divergence is a more advanced pattern: price makes a new high but RSI makes a lower high (bearish divergence), or price makes a new low but RSI makes a higher low (bullish divergence). This suggests momentum is fading before price confirms it.
SignalsDeck does not currently include divergence detection in the mechanical vote — that would require comparing peaks, which adds complexity and more false positives. The raw level vote is simpler and more consistent across dozens of coins simultaneously.
What to do with this on the dashboard
When you open a coin detail page, you see the exact RSI value alongside its vote (+1, 0, or −1). If the vote shows 0 but RSI is 31, you are close to the threshold — context matters. The AI verdict panel synthesizes this kind of nuance in plain language, explaining why the mechanical score landed where it did.
Use RSI as one lens, not the only one. The dashboard exists to aggregate multiple lenses into a single read so you do not have to.
SignalsDeck shows market data and educational analysis only. Nothing here is investment advice.