Recently, many people have asked me how to interpret the KD line. Rather than calling it an indicator, it's more like a very practical market temperature gauge. I'll share my insights from a practical perspective.

First, let's talk about the most intuitive usage. How to read the KD line? Just look at its position between 0 and 100. When the KD value exceeds 80, the market is actually a bit overheated, and buying momentum is running out of steam. At this point, be cautious of a pullback. Conversely, when KD drops below 20, it indicates that selling pressure has nearly exhausted itself, usually signaling a bottom or a rebound. Many traders rely on these 20 and 80 zones for trading because market participants tend to react quite consistently to this consensus.

But the real strength of the KD indicator lies in the fact that it consists of two lines. The K line reacts quickly, while the D line responds more slowly. When the K line crosses above the D line from below, we call it a golden cross, which is usually a bullish signal. This is especially effective when a golden cross occurs in the oversold zone (KD below 20). Conversely, when the K line crosses below the D line from above, it’s a death cross, indicating a high probability of a decline, especially if it happens in the overbought zone.

A more advanced usage is called divergence. This is my most common technique for catching tops and bottoms. For example, if the price hits a new high but the KD indicator is declining, it’s called a bearish divergence, meaning that although the price is still rising, the momentum is actually waning. At this point, consider reducing positions or hedging. Conversely, if the price continues to make new lows but the KD does not make new lows, it’s called a bullish divergence, indicating that selling pressure has passed and a rebound may follow. Long-term spot holders can consider buying on dips.

How to use this in real trading? First, remember one key point: following the trend is crucial. If the larger timeframe is bullish, a death cross on a smaller timeframe is often overwhelmed by strong buying. So don’t rely on a single signal to trade; wait for multiple signals to align. For example, when the market is in the overbought zone and a bearish divergence occurs simultaneously, the combined signals increase the confidence to short.

I often use KD together with RSI. When RSI indicates overheat and KD is above 90, and a death cross occurs, this combination has a particularly high accuracy. Last year, I used this combo to catch several good rebounds.

Of course, KD is not perfect. In a strong trending market, KD values tend to stay at extreme levels. If you only trade based on these extremes, you might get stopped out multiple times. Also, because it reacts quickly, during consolidation phases, the K and D lines often cross frequently, creating many false signals. Ultimately, how to interpret KD depends on flexible application based on market conditions. It reflects past momentum but cannot precisely predict trend reversals, so it should be used alongside other indicators and fundamental analysis.

In summary, combining overbought/oversold zones, crossover signals, and divergence phenomena can maximize the utility of the KD indicator. Remember, there is no perfect indicator—only perfect execution.