How to Read MACD: MACD Line, Signal Line, Histogram and Zero Line

The MACD line: the gap between two moving averages

MACD (Moving Average Convergence Divergence) is the difference between a fast EMA and a slow EMA. The defaults are 12, 26 and 9, and MACD line = EMA12 − EMA26. When price rises, the quicker-reacting EMA12 climbs before the EMA26, so the gap opens up in positive territory; when price falls, it opens up in negative territory. The two lines coming together is called convergence and moving apart divergence, which is where the name comes from. In the end, the MACD line shows how far the short average is above or below the long average (for the EMA itself, see the article on moving averages).

The signal line and the histogram

The signal line is the MACD line averaged again with a 9-bar EMA, and the histogram draws the MACD line minus the signal line as bars. TradingView's default MACD also uses 12, 26 and 9, with EMAs for both averages. All three components are calculated from the same closes, so they are not independent pieces of information. A histogram above 0 means the MACD line is above the signal line, and the bar where the histogram passes through 0 is the bar where the two lines cross.

• MACD line = EMA12 − EMA26
• Signal line = EMA9 of the MACD line
• Histogram = MACD line − signal line
• Zero line = where the MACD line is 0, that is, EMA12 = EMA26

A zero-line cross is an EMA12/EMA26 cross

A MACD line above 0 means exactly the same thing as EMA12 being above EMA26. So the bar where the MACD line crosses above the zero line is exactly the bar where EMA12 crosses above EMA26. Counting a 'MACD zero-line breakout' and a '12/26 EMA golden cross' as two confirmations means counting the same event twice. A zero-line cross is a moving average cross, so it carries the same lag covered in the moving average article and the same habit of flipping back and forth in sideways markets.

When the signal cross comes: after the MACD line turns, before the zero cross

The signal line is an average of the MACD line, so it moves later than the MACD line, and the cross between the two comes only after the MACD line has changed direction. The MACD line does not wait for price to bottom before turning; it turns as soon as the decline slows and the gap between the two EMAs starts to narrow. So the signal cross usually comes before the zero-line cross and sometimes appears near a price low. On the other hand, it appears whenever a decline slows briefly and then speeds up again, so it occurs more often than the zero-line cross and gets reversed correspondingly more often.

What a shrinking histogram means

The histogram is how far the MACD line is from its own average, the signal line, so it effectively shows how fast the MACD line is changing. Shrinking positive bars mean the MACD line's rise has slowed or it has started to turn, which means the gap between the two EMAs is widening more slowly. Price can keep rising all the while. In the previous figure, too, price rose about 12% further after the bar with the tallest positive histogram. Reading shrinking bars as 'the rise is slowing' fits the calculation better than reading them as 'the trend is weakening'.

Measured: share higher after signal-line crosses

On the daily bars of 10 coins on Binance (each from its Binance listing date to September 2026), we found every bar where the MACD line crossed the signal line and compared the share whose close was higher 20 bars later with the baseline measured over all bars. After upward crosses it was 51.4%, one percentage point from the 50.4% baseline, and 5 bars later it was 50.5%, the same as the baseline. After downward crosses, 55.0% actually went up. On BTC 4-hour bars, too, the share 30 bars after an upward cross was 52.1%, close to the 52.8% baseline. In this data, signal-line crosses did little to tell which way price went next.

• Baseline (all bars, 20 bars later): up 50.4%
• 1,048 crosses above the signal line: 51.4%
• 1,052 crosses below the signal line: 55.0%
• 677 crosses above the signal line while below zero: 49.9%

Values are in price units

The MACD line is the difference between two prices, so it has the same units as price. When Bitcoin's MACD is in the hundreds of dollars, the MACD of a coin priced under one dollar stays in the decimals. Comparing MACD sizes across coins is therefore meaningless, as is comparing its height over a long period in which the same coin's price changed several-fold. MarketScope, which calculates from Korean exchange Bithumb's won prices, and a Binance chart priced in USDT show completely different MACD numbers even for the same coin. To compare, you have to divide by price: PPO, calculated as (EMA12 − EMA26) ÷ EMA26 × 100, is such an indicator, and the Golden & Death Cross Scanner also shows the gap between the MACD line and the signal line as a ratio to the close.

Limits: a summary that averages price twice

All three components of MACD are differences between EMAs of the close and an average of that difference, so they add no information that is not already on the price chart. Because it is built on moving averages, crosses become frequent in stretches where price moves back and forth within a range (see the article on sideways markets), and even while a trend continues, the histogram keeps shrinking and growing. Divergence, where the highs of price and the highs of MACD disagree, is covered in the divergence article in Part 6. The 12, 26 and 9 settings are simply conventions that stuck, and changing them changes when crosses occur. This article does not decide which crosses to use in trading.