Golden cross and death cross
A golden cross occurs when the 50-period moving average crosses above the 200; a death cross when it crosses below. Long-term trend signals.
These crossovers, mostly watched on daily charts of indices and large stocks, are among the most talked-about technical signals. The golden cross is read as a shift into a long-term uptrend, the death cross as the opposite.
They are slow by design: by the time the 50 crosses the 200, much of the move has often already happened. In a trendless market, they can follow one another and trap you.
Use them as a context filter rather than an entry signal: for example, only take buys while the 50 stays above the 200.