A Golden Cross occurs when a short-term moving average — most often the 50-day SMA — rises above a long-term moving average, most often the 200-day SMA. The logic: the recent trend has now become stronger than the long-run average, suggesting a sustained bullish shift in momentum.
Historically the Golden Cross has preceded several major bull market runs, which is why it attracts significant media coverage. However, it is a lagging indicator by construction — it fires after price has already moved, sometimes well after the move has run its course. It also generates false positives in sideways, choppy markets.
The Golden Cross is best understood as a broad trend-confirmation tool rather than a precise entry signal. Traders often combine it with volume analysis, market breadth, or an RSI filter to reduce whipsaw exposure. Its mirror image — the Death Cross — gives the bearish reversal signal.