When a major cryptocurrency has a sudden large - scale fluctuation, first, analyze technical indicators like moving averages (check if short - term MA crosses long - term, indicating trend change), trading volume (abnormal spikes suggest strong market participation), and MACD (divergence or convergence signals). Then, combine real - time news: policy changes (e.g., a country’s crypto regulation draft) or project updates (new feature launch). For short - term trends, if positive news matches bullish indicators, the upward may continue; negative news with bearish signals may lead to a drop.