Recently, while analyzing the market, I noticed that many people misunderstand the divergence rate indicator, thinking it has independent parameter settings. Actually, that's not the case.

The divergence rate itself has no parameters of its own; the numbers like 5, 15, 20 in trading software are actually derived from the number of days in the moving average. Simply put, the divergence rate measures how many percentage points the current price deviates from a certain moving average. If you set it to 15 days, it shows how much the price deviates from the 15-day moving average.

Why is understanding this important? Because only by understanding the principle can you truly use this tool effectively. The core logic of the divergence rate is simple: prices tend to fluctuate around the mean, and when they deviate too far, they will eventually revert. So, during extreme market conditions, whether overly bullish or bearish, this indicator can help you detect it.

The calculation method is: (closing price of the day – N-day moving average) ÷ N-day moving average × 100%. The result can be positive or negative. A positive value indicates the price is above the moving average, with larger values representing stronger FOMO; a negative value indicates the price is below the moving average, with larger absolute values indicating the market is oversold.

What are the most common combinations in the market? Short-term use 5 or 10 days, mid-term use 20 days (monthly line), long-term use 60 or 120 days. Because the crypto market operates 24/7, some people adjust the 5-day to 7 days, or change the 20-day to 30 days. These parameters are widely adopted because they align with natural trading cycles—about 20 trading days in a month, roughly 60 in a quarter.

So, what exactly is the difference between these three parameters: 5, 15, and 20? Let me explain the practical differences.

The 5-day divergence rate reacts the fastest, very sensitive to daily fluctuations, so it has the highest sensitivity but also the most noise. The 15-day divergence rate falls in between, filtering out some short-term noise while maintaining a decent response speed. Many traders find the 15 parameter to be the most balanced—it’s neither too slow nor too easily misled by short-term noise. The 20-day divergence rate is the most stable, responds the slowest, but is more accurate; the market often regards it as an important support and resistance level, and extreme values often indicate a stage top or bottom.

Are there differences in application between stock and crypto markets? Yes. The stock market has 5 trading days a week, while the crypto market operates 7 days. More importantly, their volatility differs—overbought/oversold thresholds in stocks might be around 2-3% deviation, but crypto markets are more volatile, often requiring over 5% to be considered extreme.

I’ve seen many people make a common mistake: constantly adjusting parameters to fit past market conditions, thinking this can predict the future. That’s actually overfitting. Whether parameters should be changed depends mainly on the current market state. During sideways trading, use short-term parameters to identify local highs and lows; during trending markets, use long-term parameters to avoid misleading signals.

So, what’s the best number of days to use? It really depends on your trading style. For short-term day trading, start with 5 days; for long-term investors, prioritize 20 days. Are smaller parameters more accurate? Not necessarily. Smaller parameters generate more signals, but also more false signals, which can easily mislead you into continuous stop-losses.

Finally, I want to say that the true value of setting the divergence rate lies in using the numbers to reflect market sentiment. When the market is overly bullish or bearish, prices deviate from the mean, causing the divergence rate to change. By leveraging this characteristic and the mean reversion logic, you can make more rational trading decisions. But remember, any indicator is just an auxiliary tool; ultimately, decisions should also consider your own risk tolerance.