How does the MACD indicator generate trading signals, and what is the difference between MACD crossovers and histogram divergences?

MACD (Moving Average Convergence Divergence) is a trend-following momentum indicator that captures the relationship between two exponential moving averages. It provides three types of signals: centerline crossovers, signal line crossovers, and histogram divergences.\n\nMACD Components:\n\n- MACD Line = 12-period EMA - 26-period EMA\n- Signal Line = 9-period EMA of the MACD Line\n- Histogram = MACD Line - Signal Line\n\nWhen the 12-EMA is above the 26-EMA, MACD is positive (bullish momentum). When below, MACD is negative (bearish momentum).\n\nThree Signal Types:\n\n`mermaid\ngraph TD\n A[\"MACD Signals\"] --> B[\"Signal Line Crossover\"]\n A --> C[\"Centerline Crossover\"]\n A --> D[\"Histogram Divergence\"]\n B --> E[\"MACD crosses above signal = Buy
MACD crosses below signal = Sell\"]\n C --> F[\"MACD crosses above zero = Bullish trend
MACD crosses below zero = Bearish trend\"]\n D --> G[\"Histogram peaks shrinking while
price extends = Fading momentum\"]\n`\n\nWorked Example:\nTrader Kira analyzes Foxworth Energy (FWE), currently at $72:\n\n12-day EMA: $71.40\n26-day EMA: $69.85\nMACD Line: 71.40 - 69.85 = +1.55\nSignal Line (9-day EMA of MACD): +1.20\nHistogram: 1.55 - 1.20 = +0.35\n\nInterpretation:\n- MACD is positive (above zero) -- the short-term trend is bullish\n- MACD is above the signal line -- bullish momentum is accelerating\n- Histogram is positive and expanding -- momentum is strengthening\n\nOne week later:\nPrice rises to $74, MACD = +1.72, Signal = +1.48, Histogram = +0.24\n\nThe histogram has contracted from +0.35 to +0.24 even though price rose. This is an early warning: while still bullish, the rate of momentum acceleration is declining. If the histogram crosses below zero (MACD crosses below signal), that generates a sell signal.\n\nMACD Divergence:\n\nJust like RSI divergence, MACD divergence compares the indicator's peaks/troughs with price:\n\nFWE makes a higher high at $76, but MACD peaks at +1.45 (below prior peak of +1.72). This bearish divergence suggests the uptrend is losing momentum despite higher prices.\n\nStrengths and Limitations:\n\n| Strength | Limitation |\n|---|---|\n| Combines trend and momentum in one indicator | Lagging -- based on moving averages |\n| Centerline crossovers confirm trend direction | False signals in choppy/range-bound markets |\n| Histogram provides early warnings | Default parameters (12, 26, 9) may not suit all assets |\n| Widely followed, creates self-reinforcing signals | Signal line crossovers can whipsaw in low-volatility periods |\n\nCFA Exam Tips:\n- Know the calculation: MACD = 12 EMA - 26 EMA, signal = 9 EMA of MACD\n- Understand that MACD is unbounded (unlike RSI) so there are no overbought/oversold levels\n- Recognize that MACD works best in trending markets and produces false signals in ranges\n- Divergence between MACD and price is the most powerful signal type\n\nExplore momentum indicators in our CFA course.