Reversal
A sustained change in the direction of the prevailing trend, not just a temporary counter-move.
A reversal ends one trend and starts another. It requires structural evidence — an uptrend reversal needs price to break below a prior swing low and fail to make new highs; a downtrend reversal needs the opposite sequence.
Reversals are confirmed in hindsight. In real time, the first sign is often a divergence between price and momentum, a climactic volume spike, or an extended move into a major resistance/support zone. Trading reversals carries higher risk than trend continuation because you are fighting recent momentum.