Traders often treat MACD and Stochastic as competing versions of the same idea and end up confused when they disagree. They're built to measure different things, and the disagreement is often informative rather than a flaw.
1. What each one is actually measuring
MACD is built from the relationship between two exponential moving averages, so it's fundamentally a trend and momentum tool, it tells you whether momentum is building or fading in the current direction. Stochastic compares the current close to the recent high-low range, so it's built to flag when price has moved too far, too fast relative to its own recent range, regardless of the broader trend.
2. Why Stochastic misleads in strong trends
In a strong, sustained trend, Stochastic can sit at an "overbought" or "oversold" extreme for a long stretch without price actually reversing, because the trend keeps pushing closes near the top or bottom of the recent range. Traders who treat that extreme as an automatic reversal signal get repeatedly stopped out fighting a trend that MACD would have shown was still intact.
3. A combined approach
Using MACD to establish the prevailing direction, and Stochastic only to time entries within pullbacks in that direction, keeps Stochastic's speed useful without letting its false signals fight the trend. A Stochastic oversold reading during an MACD-confirmed uptrend is a pullback-buying signal; the same reading during a downtrend is not.