The difference between K value (KDJ) and RSI exceeding 30 is essentially a sign of severe imbalance in market bullish and bearish momentum, with indicators showing extreme divergence, triggering "mean reversion," leading to a rebound or pullback.

1. Understand the two indicators first
K value (KDJ):
Range 0–100, reflects short-term price position and momentum
>80: Overbought (overextended rally); <20: Oversold (overextended decline)
RSI (Relative Strength Index):
Range 0–100, reflects the strength of bullish and bearish forces
>70: Overbought (excessive buying); <30: Oversold (depleted selling)
2. When the difference > 30: two typical situations
1. Rebound signal: K value very low, RSI very high (difference > 30)
Pattern: K <20 (oversold), RSI >50 (relatively strong)
Meaning:
K value: Price has severely oversold, short-term bearish momentum exhausted
RSI: Medium to long-term bullish strength still present, downward momentum insufficient
Conclusion: Bears have overextended, bulls may attack at any time → Rebound
2. Pullback / correction signal: K value very high, RSI very low (difference > 30)
Pattern: K >80 (overbought), RSI <50 (relatively weak)
Meaning:
K value: Price has severely overbought, short-term bullish momentum exhausted
RSI: Medium to long-term bearish strength still present, upward momentum insufficient
Conclusion: Bulls have overused their strength, bears may attack at any time → Pullback / correction
3. Why does a difference > 30 trigger a reversal?
Indicator divergence (core)
K (short-term) and RSI (mid-term) move in opposite directions, indicating trend momentum has broken
Short-term and mid-term market directions conflict, requiring price to revert to repair
Resonance of overbought and oversold conditions
When difference > 30, at least one indicator enters an extreme zone (K<20 or K>80)
Overbought must pull back, oversold must rebound (mean reversion principle)
Imbalance of bullish and bearish forces
K high, RSI low: Short-term buying overheated, medium-term selling pressure heavy → Bulls unable to continue rising
K low, RSI high: Short-term selling exhausted, medium-term buying strong → Bears unable to continue falling
4. Practical judgment (quick memory)
Rebound: K <20, RSI >50, difference >30 → Oversold + Bulls dominant → Rebound
Pullback: K >80, RSI <50, difference >30 → Overbought + Bears dominant → Pullback
5. Precautions
Not 100%: In strong trends, indicators may become dull, difference may continue to widen
Must combine with trend: In bull markets look for overbought, in bear markets look for oversold
Coordinate with volume and price: Breakouts on volume / key support or resistance levels are more effective
Summary in one sentence: K and RSI difference > 30 = extreme divergence between short-term and medium-term momentum → Market self-corrects → Rebound or pullback.