Recently, while backtesting trading systems, I started to struggle again with the MACD parameters issue. I found that many people are actually using the default 12-26-9, but they have no idea why these numbers are chosen.

Honestly, the MACD indicator itself isn’t particularly magical; it’s just three lines moving around. The fast line, slow line, and histogram each represent short-term, medium-term, and visualized responses. The key is how you set the parameters, which determines whether you can catch the right trends.

The standard 12-26-9 is indeed convenient. EMA(12) looks at two weeks of short-term momentum, EMA(26) observes about a month of long-term trend, and EMA(9) filters out noise. This set of parameters is widely used partly because of market consensus—everyone watches the same signals, so at critical moments, many will enter the market. But here’s the problem: if you’re a short-term trader or operating in a highly volatile crypto market, this set might be too smooth, making it hard to catch small-cycle opportunities.

I’ve tried many combinations myself. 5-35-5 reacts the fastest, giving signals like crazy, but it also produces a lot of noise and false signals. 8-17-9 falls somewhere in between, suitable for the rhythm of a 1-hour forex chart. 19-39-9 leans toward medium to long-term, filtering out most junk signals. 24-52-18 is the slowest, but once the trend is confirmed, it’s very stable. So, there’s no single “best” MACD setting; it all depends on your trading style.

Many people, after adjusting parameters, become obsessed with finding the “optimal” setting, which is a trap. I’ve seen too many traders deliberately fit parameters to past charts just to make backtest results look good—that’s overfitting. When they go live, they realize that the strategies based on those “perfect” signals often fail in real markets.

I previously compared Bitcoin’s half-year daily data. The 12-26-9 set produced 7 clear signals, including 2 true golden crosses that led to actual rises afterward. The 5-35-5 set generated nearly twice as many signals—13—but only 5 were effective; the rest were small ups and downs. It seems like 5-35-5 is more sensitive, but in real trading, you have to endure more false signals, and profits might not be better.

My advice is to start with the default 12-26-9 and observe for a while. Once you get used to it, you can fine-tune based on your trading habits. Short-term traders can try 5-35-5 or 8-17-9, but always backtest with your strategy first—don’t jump straight into live trading. Once you pick a set of parameters, don’t change them frequently unless you notice recent performance has significantly deteriorated. Stability often yields better results.

Some traders also use two sets of MACD parameters simultaneously to filter signals. That’s an option, but it increases the number of signals and makes judgment more difficult—testing your decision-making skills. Instead of stacking multiple parameter sets, I think it’s better to master one set thoroughly.

In summary, adjusting MACD parameters isn’t about finding the perfect numbers but about finding settings that fit your trading logic. Beginners should stick to the default values, and only after gaining experience should they adjust based on actual conditions. Remember to develop habits of backtesting and review—avoid overfitting traps—only then can you truly make good use of MACD.